In person ID requirements all rely on punishing merchants if a minor fools them with a fake ID which aligns the incentives pretty well. It's hard to imagine how that would work online. Do you go to jail/pay thousands of dollars if someone hands their phone to their kid while logged in to Facebook or Google? You would if you sold beer to a kid who was given their parent's wallet.

Without an enforcement mechanism that punishes site owners the whole system fails. And you can't reasonably expect site owners to be responsible for checking ID on every request. So, it's (practically) impossible.

> And I don't really understand the issue people have with social media and ID. You're already required to link your phone which is a massive invasion of privacy

Yep, and we* lost that argument and "think of the children" hysteria won.

* I would bet the same folks opposed to ID requirements now were opposed to phone number then