Why?

In Russia we have gosuslugi.ru (state services), which nowadays requires 2FA and hasn't been compromised in any major way so far.

Among other things they provide a way for a third party to use it as identification service and a user chooses which data about himself he wants to share. No anonymity, though, and I don't see how it can be implemented so that the verification provider doesn't know which service is requiring age verification.

These already exist in several eu countries. Imagine that there are governments that is not America and that actually work.