Comment by buildfocus

For Spain, for online stuff signatures & verification it's mtls, with a client certificate issued by the government. You can sign documents with it or authenticate with it entirely offline (effectively nobody does the latter, but you could, and signing documents with it is very common). Government has no idea how it's used. 3rd party just verifies the government has signed the cert and it's got a valid date.

There's other issues (UX, privacy to the 3rd parties) and further improvements here coming with better wallets (EU-wide) soon, but even today it's absolutely possible to have digital id that doesn't tell the government every time you use it.