The up to $17.1 billion that Meta agreed on Wednesday to pay to 47 states, the District of Columbia and some U.S. territories to settle a three-year-old lawsuit probably won’t sting that much for Mark Zuckerberg, Meta’s chief executive.

The details of the settlement, however, could leave a mark. Meta also agreed to rein in children’s access to its marquee products like Instagram and Facebook, create daily time limits, increase parental controls and cut off access during school hours.

That could permanently alter how Meta interacts with its youngest users, the next generation to scroll and click on its various apps, and make it hard for the company to uphold its claim to be the world’s dominant social media company.

Mr. Zuckerberg has a contingency plan: Level the playing field, so that children can’t just switch to the app of a competitor. If he has to play by new rules, he wants companies like YouTube and TikTok to do the same. Meta built a financial incentive into its deal with the state attorneys general, designed to rope in the other companies.

Here’s how it would work: The base line of Meta’s monetary settlement is $12 billion. The company has also agreed to a two-hour daily time limit for children. Meta will reduce that to one hour if YouTube and TikTok also agree to a one-hour limit. And if the other companies also pay $5 billion to the states, Meta will throw in the rest of the $5 billion or so it has promised.

It is not clear what sort of mechanism would be needed to make such cooperation from the other companies a reality. YouTube and TikTok have yet to publicly acknowledge Meta’s overtures. YouTube declined to comment, and representatives for TikTok did not respond to requests for comment.

On Wednesday, some lawmakers hinted at their appetite to make the rules apply to the rest of the industry. In a joint statement, Senators Marsha Blackburn, Republican of Tennessee, and Richard Blumenthal, Democrat of Connecticut, said Americans needed safeguards that applied “to all social media companies — not just Instagram and Facebook.”

That wrinkle in the settlement shows how important it is to Mr. Zuckerberg to make certain his competitors don’t have an advantage over his company when it comes to winning over young users.

It also underscores a longstanding struggle of Mr. Zuckerberg’s to ensure that Meta, which has whipsawed over the years from big investments in the so-called metaverse to artificial intelligence, stays relevant with the consumers whose advertising consumption pays the bills.

For more than two decades, Meta has maintained its dominant position by persuading generations of young people to download and become repeat users of its apps. In a digital world where tech companies rise and fall with the whims of consumer taste, anything that could interrupt that cycle is very dangerous.

In a company blog post titled “An open letter to TikTok and YouTube to join us in supporting teens,” Meta pressed those other companies to abide by similar restrictions. The company published the letter shortly after announcing its settlement on Wednesday morning.

Silicon Valley has largely managed to stave off child safety concerns by highlighting controls that shift responsibility to parents. Mr. Zuckerberg and his peers have grown accustomed to regular appearances on Capitol Hill. Despite more than a dozen congressional hearings, nothing much happened.

But in 2023, Meta was sued by more than three dozen states that accused it of knowingly using features on Instagram and Facebook to hook children on its platforms, even as the company said its social media sites were safe for young people.

Other lawsuits piled up. In March, Meta and YouTube lost their first personal injury case, resulting in $6 million in damages. This month, a New Mexico judge ordered Meta to pay penalties totaling nearly $1 billion for violating consumer protection laws.

As YouTube and TikTok struck settlement deals, some Meta executives worried their critics were closing in, according to two people who spoke on the condition of anonymity. Seven days into the last trial, Meta saw the writing on the wall: It was time to settle.

The financial terms of Meta’s deal could be considered a bargain. Meta’s current market capitalization hovers around $1.45 trillion. The company recorded a $18.3 billion profit in its last quarter. And it will spread out its payments to the states over 10 years. In time, those payments are likely to be but a blip in Meta’s quarterly financial results.

“$17 billion sounds like accountability, until you look at the numbers,” said Lisa Strohman, a clinical psychologist and founder of Digital Citizen Academy, an organization focused on addressing technology addiction and overuse. “Even the maximum settlement represents only about 8.5 percent of one year’s revenue.”

But changes to the apps could be a real problem. No more push notifications to children during school hours, beefed-up age-verification tools and a hard two-hour daily time limit on those apps all add up to reduced engagement.

If enforced — and Meta has a history of not entirely living up to its deals with regulators — the changes could kneecap Meta’s ability to attract new users while competitors don’t have to abide by the same rules.

Now Mr. Zuckerberg says his company wants to take the lead in “setting a new industry standard” for child safety online.

Meta called for its peers to join the company and voluntarily adhere to the standards it is expected to follow. “These protections will only be truly effective if we work with our peers — TikTok and YouTube — to put the same measures in place,” the company said in its blog post.

On Thursday, Meta plans to take out full-page advertisements in The Washington Post, The Los Angeles Times and The New York Times. The company said it wanted to “empower parents” and “ensure teens use social media in a healthy and responsible way.”

Meta’s critics say the company is making a cynical grab for public good will.

“This attempt to position themselves as the good guys is just another Meta P.R. campaign,” said Sacha Haworth, founder and executive director of the Tech Oversight Project, a nonprofit watchdog organization.

Henry Coan, founder of Interrupt Studios, an advertising firm, said in an interview that he was reminded of an episode of “Mad Men,” the hit television series about an advertising firm set in the 1960s. When the agency lost its contract with Lucky Strike, the cigarette purveyor and its largest client, the lead character wrote an open letter to The New York Times claiming the firm had turned over a new leaf.

In the show, the letter’s title was straightforward: “Why I’m Quitting Tobacco.”

Cecilia Kang contributed reporting from Washington.