So, as luck would have it, today I had to fly from outside the Schengen zone into the Schengen zone with a layover.

So, passport checks, covid certificate checks, ticket checks. The ticket is non-resellable, non-refundable, non-transferrable to another person.

Guess how many of those steps required a blockchain. Also guess how many of those steps simply worked, and didn't need a blockchain.

Edit: Also worth noting: I bought the ticket through what is essentially a reseller (an aggregator site), and I could verify the ticket's authenticity with the organizer (the air company). Guess how many of these steps needed a blockchain to work.