[srmarm]

That's the bit that gets me confused, with cryptocurrencies there is a clear link between the computer processing and the 'thing' you're representing (i.e crypto hashes).

With say a digital vaccination passport the 'thing' you're wanting to prove is that someone is vaccinated and the interface between the blockchain and the real world still requires a trusted central party(s) - whoever certifies the efficacy and safety of the vaccine, that the batch is legit and that it was actually administered competently and to the person in this case.

As with many of these applications there doesn't seem to be an existing problem with a trusted central party or immutability to solve