> Isn’t that the entire point of government ID of any variety?

Ideally this could be done without deanonymizing accounts to service providers unless the user wants to for a 'verified' account linked to their identity publically but I don't think any digital ID system has been built that way. Imagine it acting like OAuth but instead of passing back an identity token it's just verification of age, platforms would store that which would show they had performed the age verification and could be used for other age gates if there are any.

That's how EU's digital wallet is supposed to work:

> The selective disclosure of attributes will allow you to only share the specific information requested by a service provider, without revealing extra information.

> For example, with the selective disclosure of attributes you could choose to share your date of birth, but without revealing any other identifying details that could be used for profiling.

https://ec.europa.eu/digital-building-blocks/sites/spaces/EU...

You're totally right that it would be easy from a tech perspective to do that. it's a shame that:

(A) most people cannot grasp how it could be that "GovSSO" can attest "This person you just sent our way just logged into GovSSO [with biometric 2FA], and they are at least 16 years old" without the receiving system having any way of knowing who that citizen is or even whether they're 16 or 99.

(B) very real terrible government policies the UK has (like jailing people for speech, and like demanding encryption backdoors that compromise the security, at minimum, of the whole of every British citizen's devices, and at worst every device in the world) incline anyone who's paying attention to assume that the government will somehow use anything related to "ID" and "internet" to do idiotic things like figuring out who owns a Twitter account that committed some wrongspeak so the bobbies can come round them up.

You just described OpenID