> At glance this looks reasonable but how do you enforce that kids connection always goes through the parents control?

YouTube doesn't, the parent does.

> no anonymous connections are possible anymore to the entire Internet

Adults would not be blocked if I understand the GP comment. It's an age recommendation and it's up to the parent's to control it for their kids.

> we want to allow parents to control their kids.

Yes. Google, YouTube, AI in general will never be a replacement for parenting and they should drop the charade now.