The UK announced a ban of social media for those under 16. When you try to ban people from doing something they find ways to do it illegally. Humans have a need to socialize and kids are not going to stop using the internet for that just because of some law.

Aided by their parents, I'm sure, they will find seedier ways to do this. Ways that are not regulated at all, even by sensible laws that prevent direct exploitation. The parents obviously don't care that their kids use social media, otherwise they would take steps to stop them.

These laws are not going to bring back the days where we all were riding our bikes outside and reading physical books. That's not the way of life for these kids. But it's, very likely, going to put children in a more dangerous situation as they try to find some kind of solution to their social needs online.