Government IDs for age assurance: from selfies to zero-knowledge proofs
educatedguesswork.org
educatedguesswork.org
This would allow you to confirm you hold an identity (example being over 21, or having a permit) without the central authority being able to use the identity to track you or such.
A fantasy exams: you need an ID or license to fly an aircraft or to buy liquor. Zero trust zero knowledge let's you proof you have the right to do so, but that isn't trackable to a real identity or person.
But obviously, if you want to fly an airplane we need to verify that the credential was actually issued to the person standing in front of us and they didn't just give their phone away.