If you take "the bonafide original" to mean the government-issued ID, then obviously only the government-issued ID is boner-fido. But there's no reason why that should be my only ID; I could, for example, generate my own keypair, and hire a notary public to attest that the holder of the keypair is (select any):

[] Good for ten-grand

[] Older than 18/21

[] The person shown in the accompanying (signed) photo

[] The author of xyz.blog

[] The same person as government-ID xxxxx

Only the last needs to be linked to a government ID, but all the others are authentic, bonafide attestations.

And such an ID would not be a duplicate of anything (not sure why you mentioned duplicates; passports, bus-passes and driving licences can all be duplicated).

They could produce their parents, or any witness of their birth.

They could (if they were born wealthy) produce a hallmarked silver spoon engraved with their name. Not proof, but persuasive.

They could produce their 21-year-old younger sister, who has government ID (yeah, I know, that is a resort to government ID).

Best of all: they could produce a birth certificate, signed by a doctor (not itself government ID, just a prerequisite to getting a government ID).

1. How would you verify that's actually their relative and not a friend or stranger? 2. How do you verify that they are in fact the older sibling and not just saying they are?

Never heard of it. Is it an extension of FIDO2?