China already has such legislation. They have placed restrictions on social media and internet use for children, and they censor content on these platforms.
Personally, I'm against government intervention for this sort of thing. I prefer government to be constrained to securing my liberties, rather than restricting my behavior "for my own good".
As a parent, I talk to my kids about social media like I talk to them about junk food. I want them to recognize that it's bad for them - it's addictive, and provides short term pleasure that results in long term misery. Avoiding it, or making good decisions about how you interact with it, is a personal responsibility issue.
Is it possible that the current form of social media is actually contributing to the erosion of your liberties because it is so widely used in society and is likely contributing to polarization and antisocial behavior?
I see this (and, honestly, most problems) as much more than a personal responsibility issue. To me, it’s an issue of misaligned incentives and unpriced downside costs. It’s clear that market forces push companies to build an addictive service that produces long term misery. It’s also clear that social media has a cost on its users (producing long term misery, reducing acute productivity) But this cost is not paid by the social media company.
I’d argue that widespread use of the social media that today’s market incentives create is bad for society as a whole, not only for any one individual. Correcting market incentives that don’t align with social good is, in my opinion, one of the most essential purposes of legislation.