This is in complement to PKI - you still have to divulge what or how you know something with PKI in the examples given.

And you still have to do that with ZKPs. Otherwise, I can just "borrow" my buddy's license and get into a pub. Unless the ZKP will interface with a biometric authentication system and do something like facial recognition.

And even then, it hand-waves away the issues with revoked licenses. How do you do license revocation with ZKPs?