We need a German to chime in with whatever word describes this scenario, when someone suggests an action is not worth doing because of corner cases or inability to perfectly execute a process.

In this hypothetical, let's say we'd tackle the dark web passport market issue when we get there.

Passports have digitally signed certificates in them, readable by any device with an NFC radio. It's easy enough to extract that data with a mobile app, and now you have an unforgeable file that can be hashed. Of course whether users will bother to sign up for something like a social network if they have to go rummage around and find a passport, install a mobile app etc, I don't know. But it's technically possible and I've proposed such a scheme years ago. For bonus points do the hashing inside a secure enclave so the ePassport data is never upload to a remote server in the clear.