It's got nothing to do with what committee decides what the expiry is and how they then enforce it. The thing that certs and passports have in common is unrelat

It's got nothing to do with what committee decides what the expiry is and how they then enforce it. The thing that certs and passports have in common is unrelated to whether the issuer is a governmental body or not. They're both centrally revokable, attested assertions of identity, where the attestation can be validated with the attester offline. If you try and come up with a design for any system that includes this type of assertion, you'll end up in a place where you'll probably want it to expire and need re-validation at some point. That expiry is a property of the attestation, and is therefore controlled by the person/group doing the attestation. In the case of a passport, this happens to be the government. For a cert, it's the CA.