Your story seems to have far more going on than social media, and I question how it conflates something as extreme as estrangement with rules being imposed specifically regarding the subject at hand. Because there would be some serious personal issues on your end if you were abandoning family due to their limiting your social media access.

Yeah, kids can find their way around a lot of things if they really want. A parent’s job is to limit everyday harm within reason, and prevent the directly harmful ones like drinking and driving or whatever. Yeah, kids need rules too, you can’t not have them. Within reason.

As a parent there are a lot of ways you can prevent social media use, and with modern tech it’s pretty easy - along with multiple honest discussions about why social media use can have negative effects on people, and the fact that yes, they will indeed be given access to social media at some legit point that isn’t stupid like “When you are 18…”

Unfortunately there is no way to sufficiently regulate social media to prevent the access you describe. The corpos don’t want it because it would place the cost of designing, monitoring, and responsibility for such a system on them. People don’t want government interference in free speech and always bring up slippery slope arguments. And there would always be those, kids and content makers, trying to find their way around the rules. So it’s up to parents to, y’know, make rules and be parents.