There are (at least) two problems to solve. The first is to anonymously verify properties about the user (e.g. age) and the second is to only allow the legitimate person verify themself.

An national electronic id would provide users with the possibility to verify their age, that they are a physical person and so on, but in the basic case it gives their identity away to any system they use. Letting someone else use your id-card is in many countries illegal and comes with possible negative consequences. Share access to my e-id would allow them to access my bank account, take loans in my name, file for tax returns and a whole bunch of other stuff. So: e-id is not anonymous but usually kept from unauthorized use.

One solves the anonymity part. Is the document in the encrypted blob accessible by the user? Can my identity be shared with websites? Basically: what stops someone from sharing their One passkey? What stops me from letting my AI agents use it, share it with my younger cousin or sell it online?