The root issue here is that most people do not know how identities based on public/private keys work. So the stuff about using bluetooth and and QR codes is jus

The root issue here is that most people do not know how identities based on public/private keys work. So the stuff about using bluetooth and and QR codes is just a pointless and meaningless ritual. If anything goes wrong the user will have no idea about what they should do to resolve that issue. They won't know what they have to do to prevent things from going wrong. The modern cryptography that this stuff is based on was invented only 40 years ago. There is as of yet no useful cultural context to base systems on. You can't expect people to be able to use concepts that don't really exist yet.