The state already tells adults what content they can consume. Truth in advertising laws, pornography restrictions, MPAA ratings and age restrictions, pirated media, and so on. Even with a default of freedom of speech, the state has numerous subsidy/financial-penalty mechanisms by which it can and does restrict what content is practically available for consumption.

I'd prefer facebook to not give away free drugs to the drug addicts.

Social media is one of the most insidious addictions, it doesn't cost money and your physical health is largely unimpacted. The real impact is on society and the family. My Facebook addict mother could be talking to friends, reading a book, or doing anything mentally/physically/socially productive other than scrolling for hours looking at junk content and AI slop.

A parent of young children could be interacting with their kids and building lasting connections instead of scrolling through tiktok to watch the mommy bloggers interacting with their kids. Or alternatively, setting unrealistic expectations of what a good parent does for their children and basically saying anyone not doing the same is a bad parent. My parents loved me and gave me a great childhood but my working mom wasn't up at 4am making trad wife breakfasts and lunches in the kitchen. My wife likes watching that stuff. I always point out how fancy of a kitchen the trad wife has and that she can afford to spend hours a day baking and cooking because she is wealthy, doesn't need to work a 9-5, and likely has a nanny to take care of the kids while she's filming and editing daily content. These aren't baking recipes being shared, this is content implying that to be a good mother you need to only shop at Whole Foods and bust your ass in the kitchen for hours on end.

A young adult is consuming vast amounts of unrealistic body imagery (whether it's "fitness" influencers or porn) and harming themselves to achieve the same. Sure, a fat and ugly person doesn't attract the same views as fit and pretty person but it turns a dark corner when the algorithm starts pushing ED content.

Grandpa is addicted to false or misleading political feeds to the point where he's near militant in his support for someone that's more interested in leveraging identity politics for power and money than actually helping improving the life of someone like grandpa. I'm still convinced that the vast amount of radical/alarmist traditional and social media my grandfather was fed manifested into depression and contributed to his suicide.

I don't think there needs to be strong limits on the content itself. Maybe some restriction on outright lies if it's not presented as entertainment or fiction. But what needs to happen is some sort of rollback on how good these feed algorithms are. It's not really healthy and no one except the social media companies are truly benefiting at the end of the day.