What you are missing is that it's not enough for a fraction of devices to have parental control.

If you want kids to not access social networks, you need to have most of them out. If only a minority is out, they will just be outcast.

That said, "everybody must do that thing that Apple does" may be a very good example of good regulation. IDK what Apple does, though.

Apple does parental controls right. The easy path is parental controls.

Companies like epic and Microsoft dont. The easy path is just a default install

I suspect this is by design.