When the media titans Brian Roberts, John Malone and Barry Diller cast off in early February on Mr. Diller’s 156-foot, two-masted yacht, named Arriva, the waters off the coast of Jupiter, Fla., were placid.

The same could not be said for their sprawling entertainment businesses.

The three men meet occasionally to discuss the state of the industry, and lively disagreements have a been a staple of their discussions. But by the time they met on the yacht, they had all agreed that the money-losing status quo in the streaming business was unsustainable. The old cable model was a melting ice cube.

But what will take its place?

“There was peace in the valley for a period of time,” Mr. Malone mused in a rare recent interview, recalling the days before video-streaming upended the lucrative cable business. “Now, it’s quite chaotic.”

That is likely an understatement: The once-mighty Paramount, which owns the famed Paramount studio, CBS and a bevy of cable channels, recently replaced its chief executive and failed to sell itself after months of negotiations. Warner Bros. Discovery is frantically paying down its $43 billion in debt. Disney laid off thousands of workers and pushed out its chief executive as streaming losses mounted, and had to fend off a proxy contest from the activist investor Nelson Peltz.

The stocks of legacy media companies are a fraction of their former highs: Paramount is near $10 a share and Warner Bros. Discovery is hovering around $7, both down drastically from levels reached during the past year. Even Disney, at about $102, is down more than 16 percent from the price reached in March.

No wonder: Paramount, the media empire controlled by Shari Redstone, lost $1.6 billion on streaming last year. Comcast lost $2.7 billion on its Peacock streaming service. Disney lost about $2.6 billion on its services, which include Disney+, Hulu and ESPN+. Warner Bros. Discovery says its Max streaming service eked out a profit last year, but only by including HBO sales through cable distributors.

At the same time, shares of the disrupters — Netflix and Amazon — are close to record highs.

Mr. Malone, Mr. Roberts, and Mr. Diller all came of age during the golden era of television. Mr. Malone, 83, clawed his way to a multibillion dollar fortune by building a cable empire, and is an influential shareholder in Warner Bros. Discovery and a longtime mentor to its chief executive, David Zaslav. Mr. Roberts, 64, succeeded his father as chairman, chief executive and the most influential shareholder of Comcast. Since then, he has transformed Comcast into a broadband giant and, by acquiring NBCUniversal, into a media powerhouse. Mr. Diller, 82, is chairman of IAC, the digital media company, and a veteran TV and movie executive. His long and successful tenure in entertainment and media has earned him a position as one of the industry’s most sought-after senior statesman.

By comparison, the heads of the disrupters, Netflix and Amazon, are younger, brash newcomers, with little attachment to Hollywood’s golden age.

Ted Sarandos, 59, co-chief executive of Netflix, worked his way up through the now-defunct DVD industry before going straight to Netflix when the company was still renting DVDs by mail. Mike Hopkins, 55, head of Prime Video and Amazon MGM Studios, was steeped in digital as chief executive of Hulu, the pioneering streaming service owned by Disney, Fox and NBCU, before joining Sony as head of its television unit in 2017. He came to Amazon in 2020 and reports to the company’s chief executive, Andy Jassy, 56, who has no professional background in entertainment.

Over the past five months, The New York Times interviewed those three older executives, and the two younger ones, as well as numerous other owners and senior executives of major media companies to assess the problems facing the industry and what the future landscape could look like.

Rarely do these executives speak so candidly, on the record, about the challenge in front of them. And the meetings on the yacht aside, rarely do executives in that stratosphere get together to discuss strategy. Not only are many of them fierce rivals — Mr. Roberts famously drove up the cost of Disney’s 2019 acquisition of 21st Century Fox’s entertainment assets by bidding against Disney’s chief executive, Bob Iger — but meetings among direct competitors might attract unwelcome attention from antitrust regulators.

In our conversations, there were still plenty of disagreements, but some consistent themes emerged as well — all with major implications for investors, advertisers and audiences.

The Magic Subscriber Number

Streaming has long been hailed as a promising business, because companies like Netflix can add additional subscribers at little extra cost. The more paying subscribers a service has, the more the company’s costs can be spread out over a large base, lowering the cost per subscriber.

But those subscribers want lots of options, and the costs of making enough programming can be enormous. As a result, a streaming service’s profitability depends in large part on how many paying subscribers are needed before those TV shows and movies become cost-effective.

There was a time when industry executives hoped that number might be as low as 100 million.

But now the consensus among many of the executives interviewed is that the number is at least 200 million, and possibly more.

“If you’re going to be a full entertainment service with live sports and tent-pole blockbusters today, 200 million is a number that can give you the scale with the hope for growth over time,” Mr. Hopkins of Amazon said.

Bob Chapek, Disney’s chief executive until 2022, also agreed that 200 million was the number that meant “you’re big enough to compete.”

Netflix has reached that, and then some, with about 270 million paying subscribers. Moreover, those subscribers pay an industry-leading average of more than $11 per month.

Netflix is highly profitable, with operating margins of 28 percent. In the first quarter of 2024, Netflix reported revenue of $9.4 billion, and $2.3 billion in net income. No one else comes close.

Disney and Amazon are the only other streaming services with more than 200 million subscribers. While Amazon doesn’t disclose the number of its Prime Video subscribers, Mr. Hopkins said the number was well above 200 million and growing. Disney+ and Hulu, which is also owned by Disney, have just over 200 million subscribers combined.

In May, Disney said its entertainment streaming services eked out a small profit. Amazon doesn’t disclose profit margins or losses, and streaming is embedded in a package of Prime services. But Amazon’s chief executive, Andy Jassy, has said that Prime Video will be “a large and profitable business” on its own.

$50 Million an Episode, Over and Over

The costs of attracting — and keeping — those millions of customers is no cheap feat.

Overall, Netflix has said it will spend about $17 billion this year on programming, about what it did before last year’s Hollywood strikes depressed production. That level of spending has produced a golden age for A-list writers and actors, many of whom are flocking to the company. A new series, “3 Body Problem,” debuted a few months ago on Netflix at a reported cost of about $20 million per episode. It spent more than $200 million on “The Gray Man,” starring Ryan Gosling.

“It’s a tall order to entertain the world,” Mr. Sarandos of Netflix said. “You have to do it with regularity and dependably.”

For Netflix, $17 billion represents only about half of its total revenue. But almost no competitor can match that spending level, the executives said, except for maybe Amazon. Amazon spent $300 million for six episodes of the spy thriller “Citadel,” or $50 million per episode — one of several major bets it has made.

Not all of those pay off. But when they do, the impact can be huge, like wildcatters when they hit a gusher. Amazon paid $153 million for one season of “Fallout,” a series based on the popular post apocalyptic video game. In April, “Fallout” was the top streaming title, racking up over seven billion viewing minutes, according to Amazon.

Mr. Sarandos held out the company’s recent “Baby Reindeer” series as a prime example of why companies have to keep spending: because viewers expect a nearly endless supply of options, or they will hit the unsubscribe button.

“When you finish ‘Baby Reindeer,’ there’s something else just as good,” he said. “I worry that this notion of these other services, that they have nothing to watch problem, and that once you do a show and then you drag it out over 10 weeks or doing one episode at a time, you still end up in the same place, which is there’s nothing to watch after it.”

The data appear to bear him out. When cable TV was in its heyday, 1.5 to 2 percent of subscribers churned monthly, abandoning or suspending their service. The average churn across all streaming services is more than double that, according to data from analytics firm Antenna, with the churn rate of some smaller streaming services, like Paramount+, as high as 7 percent. Only Netflix has a churn rate below 4 percent.

Some executives who oversee rivals to Netflix and Amazon say their companies can reduce spending by only producing hits. But that’s been the holy grail ever since Hollywood was created, and no one has succeeded over the long term. Even Disney’s Marvel franchise has stumbled at the box office lately.

That means streaming services need the resources to invest in a wide variety of projects, knowing there will be some, even many, relative failures for every hit. (“Citadel” is a case in point — it never made Nielsen’s top 10 streaming shows.)

“It’s still more art than science,” Mr. Sarandos said.

Play Ball

Adding to the cost pressure, the executives said, is the soaring cost of sports programming. Even in the bygone era of traditional television, the broad appeal of sports was obvious. The big networks paid billions for must-see events like the Super Bowl and the N.B.A. Finals and much of what was left over went to Disney and Hearst-owned ESPN, one of the most lucrative cable franchises ever created.

But that was before streaming and the arrival of the deep-pocketed tech giants. Amazon now offers football games from the National Football League, NASCAR races, the W.N.B.A. with its newly minted star Caitlin Clark, the National Hockey League in Canada and Champions League soccer in Germany, Italy and Britain.

Apple TV+ also features Major League Baseball, as well as Major League Soccer.

Alphabet’s YouTube offers N.F.L. Sunday Ticket, a lineup of out-of-market football games. Even Netflix, which long shunned live sports, announced in May that it would stream N.F.L. games on Christmas Day for the next three years.

The appeal of live sports is both unique and twofold: They attract new streaming subscribers and reduce churn since viewers want to watch sports live. It is also a big draw for advertisers as streaming services look to grow their ad businesses.

It may not be an overstatement, the executives said, to say that a streaming service can’t survive as a stand-alone business without sports.

Comcast’s Peacock scored a huge success in January with its exclusive N.F.L. playoff game between Kansas City and Miami. The game was the biggest livestreaming event ever, with about 32 million viewers. (Comcast’s NBC network pays $2 billion annually for a package of N.F.L. broadcast rights.)

“Sports seems like the simplest and most interesting thing,” Mr. Malone said.

The result is bidding wars unlike anything experienced before in the media industry, currently on display during the protracted negotiations for a new 10-year N.B.A. rights contract. The rights, which are now shared by ESPN and Warner Bros. Discovery’s Turner cable network, are being chased by NBC and Amazon, as well as ESPN and Warner Bros. Discovery.

While ESPN, Amazon and NBC are finalizing deals for their packages, Warner Bros. Discovery is seen at risk of being outbid, though executives at Warner Bros. believe they have the legal rights to match Amazon’s bid. Many in the industry expect that the final deal will be more than triple the last N.B.A. contract.Which raises questions that executives didn’t have a clear answers to:

As the cost of rights soars, will the streaming services actually make money on them? Or will marquee sports events function as loss leaders, drawing viewers to other fare, as they once did for the old broadcast networks?

Advertising to the Rescue?

Wall Street analysts and investors in streaming once fixated entirely on the number of subscribers, ignoring losses, in the belief that prices would someday rise substantially. That changed with dizzying speed in early 2022, when Netflix announced it had lost subscribers for the first time in a decade.

It’s now clear that price increases won’t be the answer to streaming profitability for most services, the executives said. Netflix is the industry price leader and has pushed its monthly fee in the United States to $15.49 a month without ads. Few believe the monthly fee can get much above $20 a month for the foreseeable future.

After years of championing an ad-free consumer experience, Netflix introduced an ad-supported subscription in 2022 at a steep discount of $6.99 a month. Disney+, Hulu, Amazon, Warner Bros. Discovery’s Max, Peacock and Paramount+ all offer cheaper, ad-supported subscriptions.

“It’s a nice way to get price-sensitive consumers,” said Mr. Chapek, who introduced an ad-supported tier while running Disney. “Heavy users will still come and pay the higher monthly fee.”

Mr. Chapek acknowledged that advertisers covet — and will pay more for — mass audiences. As a result, the streaming services have a strong incentive to produce programs with broad appeal instead of more niche content, including some of the kind that generates critical acclaim.

Netflix shocked many in the industry last year when for the first time it revealed its most-watched programs over the prior six months. At the top were “The Night Agent,” an action-thriller, and “Ginny and Georgia,” a comedy-drama about a mother and daughter trying to forge a new life. Both shows were snubbed by Emmy voters, with a lone nomination for a song from “Ginny and Georgia.” (“Squid Game,” developed in Korea, is Netflix’s most-watched program ever.)

Advertisers, the executives say, also like that streaming services can target ads to specific users and demographics.

The results have been explosive. Netflix is on pace to generate roughly $1 billion in advertising revenue this year, according to estimates from eMarketer, and Disney has already generated $1.7 billion this fiscal year.

That kind of success suggests that streaming ads are here to stay. And some of the executives said streaming services predicted that companies would raise prices aggressively on ad-free tiers in an effort to drive consumers to ad-supported versions.

Who Will Survive?

How many streaming services will consumers support? That was one of the great mysteries of the nascent streaming world, and the answer is coming into focus: not very many.

“Can your current business be a successful player and have long-term wealth generation, or are you going to be roadkill?” Mr. Malone mused. “I think all the small players will have to shrink down or go away.”

A recent Deloitte study found that American households paid an average of $61 a month for four streaming services, but that many didn’t think the expense was worth it.

That suggests the once-unthinkable possibility, many of the executives said, that there will be only three or four streaming survivors: Netflix and Amazon, almost certainly. Probably some combination of Disney and Hulu. Apple remains a niche participant, but appears to be feeling its way into a long-term, albeit money-losing, presence, which it can afford to do. That leaves big question marks over Peacock, Warner Bros. Discovery’s Max, and Paramount+.

Peacock, with just 34 million subscribers, isn’t trying to be another Netflix. By focusing on North America, and not trying to be all things to all customers, Mr. Roberts believes Peacock can achieve success on its own terms.

Peacock also has the advantage to being embedded in the much larger Comcast, with its steady cash flow.

“We all have a different calculus to define success in streaming,” Mr. Roberts said. “As online viewing increases and internet usage skyrockets, I believe we have a special set of assets that put us in position to continue to monetize and more importantly innovate as this transition happens.”

The Bundling Conundrum

After years of go-it-alone strategies, “bundling” — offering consumers a package of streaming services for a single fee — has become the latest strategy for reaching profitability among the smaller services.

In May, Comcast announced it would offer its broadband customers a bundle of Peacock, Netflix and Apple TV+ for $15 a month. Disney has bundled Disney+ and Hulu, with Max to be added this summer at an as-yet undisclosed price. Venu, a new sports streaming joint venture from Disney, Fox and Warner Bros. Discovery, is planning its release this fall.

However innovative the arrangements, the executives said, the economics of bundling are complicated. Participants need to attract consumers who wouldn’t already subscribe to their individual channels at full price. They must also puzzle through how revenue should be divided among bundling participants of unequal stature.

It’s also unclear that bundling will achieve the scale that participants may be hoping for. Many customers already subscribe to one or more of the bundle options. So it’s not a matter of simply adding up subscribers. And if multiple subscriptions are offered at a discount to attract customers, the average revenue per user declines.

Jason Kilar, the founding Hulu chief executive and former chief executive of WarnerMedia, has called for an even more radical approach than bundling: a new company that would license movies and TV shows from the major studios and pay back close to 70 percent of the revenue to those studios.

“I’ll call it the ‘Spotify for Hollywood’ path, where a large number of suppliers and studios contribute to a singular experience that delights fans,” Mr. Kilar said. “The studios would be the ones that would be taking the majority of the economic returns from such a structure.”

Media companies have started to embrace licensing deals after a period of avoiding them. During AT&T’s ill-fated ownership of WarnerMedia, the company insisted that its content be shown exclusively on its Max streaming service. Disney pulled back on licensing deals when it started Disney+ in an effort to force fans to subscribe. Before he returned to Disney, in 2022, Mr. Iger compared licensing the company’s franchises to selling nuclear weapons to “third-world countries.”

But AT&T subsequently abandoned streaming, merging WarnerMedia into Discovery, and Mr. Iger has since embraced the nuclear option. Both Disney and Warner Bros. Discovery are again licensing their content to rivals Netflix and Amazon Prime.

Sony Goes Another Way

One company embodies the embrace of the licensing strategy: Sony Pictures Entertainment.

Sony, the studio behind “Spider Man” and “Men in Black,” rejected general entertainment streaming services years ago. Tony Vinciquerra, the company’s chief executive, instead adopted what he has called an “arms dealer” strategy, selling movies and TV shows to companies like Disney and Netflix.

The exception is that Sony operates a niche streamer, Crunchyroll, that focuses on anime, Japanese-style hand-dawn animation. Its success suggests that a small (more than 14 million subscribers worldwide) and low-cost operation can be profitable without going up against Netflix.

Mr. Vinciquerra pointed out that Sony’s rivals running big streaming businesses were losing money on those services while at the same time seeing their traditional cable networks in decline.

“I’m still scratching my head wondering what these companies will do here,” Mr. Vinciquerra said, referring to the declining cable networks. “They all have these massive albatrosses around their neck that they can’t do anything about right now.”

So far, Sony’s strategy appears to be working. Sony’s Pictures Entertainment generated almost $11 billion of revenue in 2023, a 2 percent increase from the same period a year earlier, according to filings. In 2021, Sony struck deals to license movies to both Netflix and Disney worth an estimated $3 billion annually. Profits were roughly $1.2 billion, 10 percent lower than the previous year because of the actors’ and writers’ strikes.

Unlike Paramount or Disney, Sony Pictures is part of a sprawling global consumer electronics conglomerate. Sony recently teamed up with the private-equity giant Apollo Global Management to make a $26 billion bid for Paramount. But Sony is interested only in Paramount’s film library and characters like SpongeBob SquarePants and has contemplated selling the rest of it — including the Paramount+ streaming service. But Sony has since backed away from its offer.

That’s just the latest indication that expectations for merger deals have faded. Paramount is still looking for a buyer after months of tortured negotiations and is revamping its streaming strategy in the meantime. So far as is known, no one is pursuing Warner Bros. Discovery, free since April, to buy or be sold under the terms of its separation from AT&T. Potential buyers like Comcast are understandably wary of their decaying revenue bases in cable. And Disney is shackled with its own cable issues and is loaded with debt from buying 21st Century Fox.

The End of a Golden Age

All of these changes have had a big upside for viewers.

“It’s been a golden age, even with prices rising,” Mr. Chapek said. “You get entire libraries built over decades plus all this new content, and you watch at your leisure.”

But a change is underway, he said: “Now we just have to make it viable for shareholders.”

That will necessarily mean higher prices for customers, more advertising, and less — and less expensive — content. That’s already happening. On average, consumers spend 41 percent more on streaming than they did a year ago, according to the recent Deloitte study, while satisfaction has declined. While some of that may be because of the limited new content offered last year during the Hollywood strikes, Disney and pretty much everyone except Netflix and Amazon have vowed to reduce spending and produce less new content.

The rise of advertising may be a windfall for streaming services, but the quest for the mass audiences that advertisers seek risks turning the streaming landscape into a sea of police procedurals and hospital dramas punctuated by major sports events and blockbuster concerts. Ironically, that’s pretty much the old model once dominated by the four ad-supported broadcast networks.

Netflix and Amazon executives acknowledge the risks to high-quality programming but promise that won’t happen on their watch. They contend they have enough scale that their prestige programs can be profitable and reach a vast audience — even if it’s a small percentage of their overall subscriber base.

“We can do prestige TV at scale,” Mr. Sarandos said. “But we don’t only do prestige,” he added, citing popular shows like “Night Agent.”

Mr. Hopkins of Amazon said “procedurals and other tried and true formats do well for us, but we also need big swings that have customers saying ‘Wow, I can’t believe that just happened’ and will have people telling their friends.”

“We want rabid fans,” he said.

Bryan Lourd, chief executive and co-chairman of the powerful Creative Artists Agency, said media executives needed to put aside financial engineering and remember that creativity — and entertaining customers — was the only way to win in the long run.

“The task at hand is to keep the customer at the front of your brain,” Mr. Lourd said. “When people stop doing that is when things start to go wrong.”

And Yet, Continued Optimism

On Mr. Diller’s yacht that day in February, Mr. Malone’s advice to Mr. Roberts was simple: In light of the challenges facing the industry, Comcast should continue its current strategy of investing in other areas like theme parks.

“Now, are they large enough to be the biggest?” said Mr. Diller, speaking generally about streaming services besides Netflix. “No, that game was lost some years ago. Netflix commands not all the territory, but they command the leading territory right now. They essentially are in a position of dictating policy.”

But Mr. Diller, like many of the other executives interviewed for this article, see a path forward for streaming companies once they stop trying to be Netflix. (That’s the strategy already adopted by Mr. Roberts of Comcast.)

The focus, according to Mr. Diller, needs to be on what “has been true since the beginning of time.”

The business, he said, “is based on hit programming, making a program, a movie, a something that people want to see.”

In April 2019, David Ginsberg, a Meta executive, emailed his boss, Mark Zuckerberg, with a proposal to research and reduce loneliness and compulsive use on Instagram and Facebook.

In the email, Mr. Ginsberg noted that the company faced scrutiny for its products’ impacts “especially around areas of problematic use/addiction and teens.” He asked Mr. Zuckerberg for 24 engineers, researchers and other staff, saying Instagram had a “deficit” on such issues.

A week later, Susan Li, now the company’s chief financial officer, informed Mr. Ginsberg that the project was “not funded” because of staffing constraints. Adam Mosseri, Instagram’s head, ultimately declined to finance the project, too.

The email exchanges are just one slice of evidence cited among more than a dozen lawsuits filed since last year by the attorneys general of 45 states and the District of Columbia. The states accuse Meta of unfairly ensnaring teenagers and children on Instagram and Facebook while deceiving the public about the hazards. Using a coordinated legal approach reminiscent of the government’s pursuit of Big Tobacco in the 1990s, the attorneys general seek to compel Meta to bolster protections for minors.

A New York Times analysis of the states’ court filings — including roughly 1,400 pages of company documents and correspondence filed as evidence by the State of Tennessee — shows how Mr. Zuckerberg and other Meta leaders repeatedly promoted the safety of the company’s platforms, playing down risks to young people, even as they rejected employee pleas to bolster youth guardrails and hire additional staff.

In interviews, the attorneys general of several states suing Meta said Mr. Zuckerberg had led his company to drive user engagement at the expense of child welfare.

“A lot of these decisions ultimately landed on Mr. Zuckerberg’s desk,” said Raúl Torrez, the attorney general of New Mexico. “He needs to be asked explicitly, and held to account explicitly, for the decisions that he’s made.”

The state lawsuits against Meta reflect mounting concerns that teenagers and children on social media can be sexually solicited, harassed, bullied, body-shamed and algorithmically induced into compulsive online use. Last Monday, Dr. Vivek H. Murthy, the United States surgeon general, called for warning labels to be placed on social networks, saying the platforms present a public health risk to young people.

His warning could boost momentum in Congress to pass the Kids Online Safety Act, a bill that would require social media companies to turn off features for minors, like bombarding them with phone notifications, that could lead to “addiction-like” behaviors. (Critics say the bill could hinder minors’ access to important information. The News/Media Alliance, a trade group that includes The Times, helped win an exemption in the bill for news sites and apps that produce news videos.)

In May, New Mexico arrested three men who were accused of targeting children for sex after, Mr. Torrez said, they solicited state investigators who had posed as children on Instagram and Facebook. Mr. Torrez, a former child sex crimes prosecutor, said Meta’s algorithms enabled adult predators to identify children they would not have found on their own.

Meta disputed the states’ claims and has filed motions to dismiss their lawsuits.

In a statement, Liza Crenshaw, a spokeswoman for Meta, said the company was committed to youth well-being and had many teams and specialists devoted to youth experiences. She added that Meta had developed more than 50 youth safety tools and features, including limiting age-inappropriate content and restricting teenagers under 16 from receiving direct messages from people they didn’t follow.

“We want to reassure every parent that we have their interests at heart in the work we’re doing to help provide teens with safe experiences online,” Ms. Crenshaw said. The states’ legal complaints, she added, “mischaracterize our work using selective quotes and cherry-picked documents.”

But parents who say their children died as a result of online harms challenged Meta’s safety assurances.

“They preach that they have safety protections, but not the right ones,” said Mary Rodee, an elementary school teacher in Canton, N.Y., whose 15-year-old son, Riley Basford, was sexually extorted on Facebook in 2021 by a stranger posing as a teenage girl. Riley died by suicide several hours later.

Ms. Rodee, who sued the company in March, said Meta had never responded to the reports she submitted through automated channels on the site about her son’s death.

“It’s pretty unfathomable,” she said.

The Push to Win Teenagers

Meta has long wrestled with how to attract and retain teenagers, who are a core part of the company’s growth strategy, internal company documents show.

Teenagers became a major focus for Mr. Zuckerberg as early as 2016, according to the Tennessee complaint, when the company was still known as Facebook and owned apps including Instagram and WhatsApp. That spring, an annual survey of young people by the investment bank Piper Jaffray reported that Snapchat, a disappearing-message app, had surpassed Instagram in popularity.

Later that year, Instagram introduced a similar disappearing photo- and video-sharing feature, Instagram Stories. Mr. Zuckerberg directed executives to focus on getting teenagers to spend more time on the company’s platforms, according to the Tennessee complaint.

The “overall company goal is total teen time spent,” wrote one employee, whose name is redacted, in an email to executives in November 2016, according to internal correspondence among the exhibits in the Tennessee case. Participating teams should increase the number of employees dedicated to projects for teenagers by at least 50 percent, the email added, noting that Meta already had more than a dozen researchers analyzing the youth market.

In April 2017, Kevin Systrom, Instagram’s chief executive, emailed Mr. Zuckerberg asking for more staff to work on mitigating harms to users, according to the New Mexico complaint.

Mr. Zuckerberg replied that he would include Instagram in a plan to hire more staff, but he said Facebook faced “more extreme issues.” At the time, legislators were criticizing the company for having failed to hinder disinformation during the 2016 U.S. presidential campaign.

Mr. Systrom asked colleagues for examples to show the urgent need for more safeguards. He soon emailed Mr. Zuckerberg again, saying Instagram users were posting videos involving “imminent danger,” including a boy who shot himself on Instagram Live, the complaint said.

Two months later, the company announced that the Instagram Stories feature had hit 250 million daily users, dwarfing Snapchat. Mr. Systrom, who left the company in 2018, didn’t respond to a request for comment.

Meta said an Instagram team developed and introduced safety measures and experiences for young users. The company didn’t respond to a question about whether Mr. Zuckerberg had provided the additional staff.

‘Millions’ of Underage Users

In January 2018, Mr. Zuckerberg received a report estimating that four million children under the age of 13 were on Instagram, according to a lawsuit filed in federal court by 33 states.

Facebook’s and Instagram’s terms of use prohibit users under 13. But the company’s sign-up process for new accounts enabled children to easily lie about their age, according to the complaint. Meta’s practices violated a federal children’s online privacy law requiring certain online services to obtain parental consent before collecting personal data, like contact information, from children under 13, the states allege.

In March 2018, The Times reported that Cambridge Analytica, a voter profiling firm, had covertly harvested the personal data of millions of Facebook users. That set off more scrutiny of the company’s privacy practices, including those involving minors.

Mr. Zuckerberg testified the next month at a Senate hearing, “We don’t allow people under the age of 13 to use Facebook.”

Attorneys general from dozens of states disagree.

In late 2021, Frances Haugen, a former Facebook employee, disclosed thousands of pages of internal documents that she said showed the company valued “profit above safety.” Lawmakers held a hearing, grilling her on why so many children had accounts.

Meanwhile, company executives knew that Instagram use by children under 13 was “the status quo,” according to the joint federal complaint filed by the states. In an internal chat in November 2021, Mr. Mosseri acknowledged those underage users and said the company’s plan to “cater the experience to their age” was on hold, the complaint said.

In its statement, Meta said Instagram had measures in place to remove underage accounts when the company identified them. Meta has said it has regularly removed hundreds of thousands of accounts that could not prove they met the company’s age requirements.

Fighting Over Beauty Filters

A company debate over beauty filters on Instagram encapsulated the internal tensions over teenage mental health — and ultimately the desire to engage more young people prevailed.

It began in 2017 after Instagram introduced camera effects that enabled users to alter their facial features to make them look funny or “cute/pretty,” according to internal emails and documents filed as evidence in the Tennessee case. The move was made to boost engagement among young people. Snapchat already had popular face filters, the emails said.

But a backlash ensued in the fall of 2019 after Instagram introduced an appearance-altering filter, Fix Me, which mimicked the nip/tuck lines that cosmetic surgeons draw on patients’ faces. Some mental health experts warned that the surgery-like camera effects could normalize unrealistic beauty standards for young women, exacerbating body-image disorders.

As a result, Instagram in October 2019 temporarily disallowed camera effects that made dramatic, surgical-looking facial alterations — while still permitting obviously fantastical filters, like goofy animal faces. The next month, concerned executives proposed a permanent ban, according to Tennessee court filings.

Other executives argued that a ban would hurt the company’s ability to compete. One senior executive sent an email saying Mr. Zuckerberg was concerned whether data showed real harm.

In early 2020, ahead of an April meeting with Mr. Zuckerberg to discuss the issue, employees prepared a briefing document on the ban, according to the Tennessee court filings. One internal email noted that employees had spoken with 18 mental health experts, each of whom raised concerns that cosmetic surgery filters could “cause lasting harm, especially to young people.”

But the meeting with Mr. Zuckerberg was canceled. Instead, the chief executive told company leaders that he was in favor of lifting the ban on beauty filters, according to an email he sent that was included in the court filings.

Several weeks later, Margaret Gould Stewart, then Facebook’s vice president for product design and responsible innovation, reached out to Mr. Zuckerberg, according to an email included among the exhibits. In the email, she noted that as a mother of teenage daughters, she knew social media put “intense” pressure on girls “with respect to body image.”

Ms. Stewart, who subsequently left Meta, did not respond to an email seeking comment.

In the end, Meta said it barred filters “that directly promote cosmetic surgery, changes in skin color or extreme weight loss” and clearly indicated when one was being used.

Priorities and Youth Safety

In 2021, Meta began planning for a new social app. It was to be aimed specifically at children and called Instagram Kids. In response, 44 attorneys general wrote a letter that May urging Mr. Zuckerberg to “abandon these plans.”

“Facebook has historically failed to protect the welfare of children on its platforms,” the letter said.

Meta subsequently paused plans for an Instagram Kids app.

By August, company efforts to protect users’ well-being work had become “increasingly urgent” for Meta, according to another email to Mr. Zuckerberg filed as an exhibit in the Tennessee case. Nick Clegg, now Meta’s head of global affairs, warned his boss of mounting concerns from regulators about the company’s impact on teenage mental health, including “potential legal action from state A.G.s.”

Describing Meta’s youth well-being efforts as “understaffed and fragmented,” Mr. Clegg requested funding for 45 employees, including 20 engineers.

In September 2021, The Wall Street Journal published an article saying Instagram knew it was “toxic for teen girls,” escalating public concerns.

An article in The Times that same month mentioned a video that Mr. Zuckerberg had posted of himself riding across a lake on an “electric surfboard.” Internally, Mr. Zuckerberg objected to that description, saying he was actually riding a hydrofoil he pumped with his legs and wanted to post a correction on Facebook, according to employee messages filed in court.

Mr. Clegg found the idea of a hydrofoil post “pretty tone deaf given the gravity” of recent accusations that Meta’ s products caused teenage mental health harms, he said in a text message with communications executives included in court filings.

Mr. Zuckerberg went ahead with the correction.

In November 2021, Mr. Clegg, who had not heard back from Mr. Zuckerberg about his request for more staff, sent a follow-up email with a scaled-down proposal, according to Tennessee court filings. He asked for 32 employees, none of them engineers.

Ms. Li, the finance executive, responded a few days later, saying she would defer to Mr. Zuckerberg and suggested that the funding was unlikely, according to an internal email filed in the Tennessee case. Meta didn’t respond to a question about whether the request had been granted.

A few months later, Meta said that although its revenue for 2021 had increased 37 percent to nearly $118 billion from a year earlier, fourth-quarter profit plummeted because of a $10 billion investment in developing virtual reality products for immersive realms, known as the metaverse.

Explicit Videos Involving Children

Last fall, the Match Group, which owns dating apps like Tinder and OKCupid, found that ads the company had placed on Meta’s platforms were running adjacent to “highly disturbing” violent and sexualized content, some of it involving children, according to the New Mexico complaint. Meta removed some of the posts flagged by Match, telling the dating giant that “violating content may not get caught a small percentage of the time,” the complaint said.

Dissatisfied with Meta’s response, Bernard Kim, the chief executive of the Match Group, reached out to Mr. Zuckerberg by email with a warning, saying his company could not “turn a blind eye,” the complaint said.

Mr. Zuckerberg didn’t respond to Mr. Kim, according to the complaint.

Meta said the company had spent years building technology to combat child exploitation.

Last month, a judge denied Meta’s motion to dismiss the New Mexico lawsuit. But the court granted a request regarding Mr. Zuckerberg, who had been named as defendant, to drop him from the case.

Deb Schmill has become a fixture on Capitol Hill. Last week alone, she visited the offices of 13 lawmakers, one of more than a dozen trips she has made from her home near Boston over the past two years.

In each meeting, Ms. Schmill talks about her daughter Becca, who died in 2020 at age 18. Ms. Schmill said Becca had died after taking fentanyl-laced drugs bought on Facebook. Before that, she said, her daughter was raped by a boy she had met online, then was cyberbullied on Snapchat.

“I have to do what I can to help pass legislation to protect other children and to prevent what happened to Becca from happening to them,” Ms. Schmill, 60, said. “It’s my coping mechanism.”

Ms. Schmill is among dozens of parents who are lobbying for the Kids Online Safety Act, or KOSA, a bill that would require social media, gaming and messaging apps to limit features that could heighten depression or bullying or lead to sexual exploitation. The bill, which has the greatest momentum of any broad tech industry legislation in years, would also require the tech services to turn on the highest privacy and safety settings by default for users under 17 and let youths opt out of some features that can lead to compulsive use.

Modeling themselves in part on Mothers Against Drunk Driving, which pushed for the 1984 federal law mandating a minimum drinking age of 21, about 20 of the parents have formed a group called ParentsSOS. Like members of MADD, the parents carry photos of their children who they say lost their lives because of social media, and explain their personal tragedies to legislators.

Dozens more parents have created organizations to fight social media addiction, eating disorders and fentanyl poisoning. All are pushing KOSA, swarming Capitol Hill to share how they say their children were harmed.

The bill, introduced in 2022, has bipartisan support in the Senate and is poised for a vote. It recently passed a key House subcommittee vote. President Biden has also supported the bill.

Dr. Vivek Murthy, the U.S. surgeon general, said this week that social media had contributed to an “emergency” mental health crisis among youths, adding more momentum.

But KOSA still faces steep obstacles. Tech lobbyists and the American Civil Liberties Union are fighting it, saying it could undermine free speech. Others worry that limiting children’s access to social media may further isolate vulnerable youths, including those in the L.G.B.T.Q. community.

To amp up the pressure as Congress’s August summer break approaches, ParentsSOS launched a Father’s Day ad campaign in Times Square, in New York, and a commercial campaign on streaming TV. (Fairplay, a child advocacy nonprofit, and the Eating Disorders Coalition provided funding.)

“I’ve had friends say, ‘Just let go and move on because it’s so painful,’ but I could not be quiet about what I’ve learned, which is that social media companies don’t have any accountability,” said Kristin Bride, 57, who lives in Oregon. Her son Carson died by suicide in 2020 at the age of 16 after what she said had been relentless bullying via an anonymous messaging app connected to Snapchat.

Snap, X and Microsoft have said they support KOSA.

“The safety of young people is an urgent priority, and we call on Congress to pass the Kids Online Safety Act,” Snapchat’s parent company, Snap, said in a statement. Snap no longer allows anonymous messaging apps to connect to its platform.

YouTube and Meta, which owns Facebook and Instagram, declined to comment. TikTok did not respond to a request for comment.

The parents’ push aligns with a global movement to regulate youth safety online. The European Union’s Digital Services Act of 2022 requires social media sites to block harmful content and restricts the use of features that can lead to addictive use by youths. Last year, Britain adopted a similar online safety law for children.

Domestically, 45 state attorneys general have sued Meta over allegations that it harms young users. Last year, 23 state legislatures adopted child safety laws, and this week New York adopted a law that restricts social media platforms from using recommendation feeds that could lead to compulsive consumption by users under 18.

Many of the parents turned lobbyists cited “The Social Dilemma,” a 2020 documentary about social media harms, as a call to action. They said they were also enraged by revelations in 2021 by the whistle-blower Frances Haugen, a former Facebook employee who testified in Congress that the company knew the dangers for young people on its apps.

“For the first time, I understood that it was the design, it was the companies,” said Christine McComas, 59, who lives in Maryland. She said her daughter Grace died at 15 by suicide in 2012 after being bullied on Twitter.

Many of the parents said the Center for Humane Technology, a nonprofit that advocates social media regulations and was part of the documentary, had connected them after they reached out.

Maurine Molak’s son David died by suicide in 2016 at age 16 after what she said had been cyberbullying on Instagram and messaging apps. Another of her sons found an online memorial page for Grace McComas and encouraged his mother to get in touch with Ms. McComas via email.

The two mothers began having phone calls and connected with other parents, too. Ms. Molak had set up a foundation to educate the public about online bullying and to push for anti-bullying state legislation.

By early 2022, some of the parents had begun working with Fairplay to push for state child safety laws. That February, Senators Richard Blumenthal, Democrat of Connecticut, and Marsha Blackburn, Republican of Tennessee, introduced KOSA.

It had early but modest support, moving out of a Senate committee before stalling for months. Growing impatient, several parents showed up on Capitol Hill that November. Ms. Bride and other parents said they had entered the office of Senator Maria Cantwell, chair of the Commerce Committee and Democrat of Washington, and demanded a meeting. She met with them the next day.

Ms. Cantwell was visibly moved and rubbed the backs of several parents as they talked about their children, Ms. Bride said.

“Having to look at us and to know that our children are no longer with us hits them, and it has gotten people on board,” Ms. Bride said. Ms. Cantwell’s office declined to comment.

Ms. Cantwell became a vocal supporter of the bill, then tried to attach it to a year-end spending bill, which failed.

For much of last year, the bill sat, in part over concerns that the language requiring companies to design sites to protect children was too vague. Some legislators were also concerned that the bill would give attorneys general too much power to police certain content, a potential political weapon.

Discouraged, the parents called one another to stay motivated. In September, Ms. Schmill rented a short-term apartment a 10-minute walk from the Capitol. She changed in and out of sneakers carried in a canvas bag as she visited the offices of nearly all 100 senators to tell them about Becca.

“As I thought about facing another year of her birth date and death date, for me to cope with having to live through another anniversary, I had to feel like I had to be doing something productive in her memory,” Ms. Schmill said.

Late last year, around the time the Senate Judiciary Committee announced a January hearing on child safety with tech chief executives, the parents decided to form ParentsSOS. The initiative, intended to help them gain more support for KOSA, was funded by Fairplay and Ms. Molak’s foundation focused on cyberbullying.

The parents — communicating in emails and texts and over Zoom — decided to go to the child safety hearing to confront the executives from Discord, Meta, Snap, TikTok and X with photos of their children.

At the hearing, Senator Josh Hawley, Republican of Missouri, tried to force Mark Zuckerberg, Meta’s chief executive, to apologize to the parents. Mr. Zuckerberg turned to the parents and said he was “sorry for everything you’ve all gone through.”

Todd Minor, a member of ParentsSOS who was in attendance, said the apology rang hollow. His 12-year-old son, Matthew, died in 2019 after taking part, Mr. Minor said, in a “blackout challenge” on TikTok, in which people choke themselves.

“We need KOSA. It’s that simple,” Mr. Minor, 48, said.

The parents then met with the Senate leader, Chuck Schumer, Democrat of New York, who promised to bring KOSA to a floor vote by June 20, according to Ms. Schmill and others in the meetings.

In April, the House introduced a companion bill.

Ms. Molak, 61, a San Antonio resident, met with Representative Randy Weber, Republican of Texas, last month to talk about her son David.

“Why am I not on this bill? Let’s get on this!” Mr. Weber, a member of the House Energy and Commerce Committee, said to his staff during the meeting, according to Ms. Molak. Mr. Weber’s office did not respond to a request for comment.

But progress in that committee stalled this month. The Senate version of the bill still faces opposition.

Ms. Schmill and three of the other parents trekked back to the Capitol again last week.

“I need to keep busy, to keep trying,” Ms. Schmill said.

If you are having thoughts of suicide, call or text 988 to reach the 988 Suicide and Crisis Lifeline or go to SpeakingOfSuicide.com/resources for a list of additional resources.