What you don’t realize is most people want this. The social media bans across Western Europe, and Australia are heavily supported by the vast majority of the population.
Yep, here in Australia you almost never hear anyone mention it. The silence is deafening, especially with how quickly people just rolled over on this stuff "For the children".
That said it was funny, yesterday Microsoft said I had to age verify my account. I went in basically with the intention of backing out of it at the first sign of over reach.
First step was, 'provide you email for this account'. So I did that and then... approved! You are certified over 18+. That is the flip side of this, some of these companies will put up some of the weakest barriers on this stuff.
You could make it easy to ban on children's devices, rather than having websites do it. At the moment you either have a small set of allowed applications, which is fine for younger kids, or domain-list filtering which is unreliable, hard for parents to set up (and not that hard for kids to get around). There are many ways to improve the situation – I think websites should have to attach metadata about the content being served, browsers should use this to apply a device policy, and devices should make it easy to configure basic rules on first setup. People aren't asking specifically for hardware-attested facial scanning