[Oxidation]

Even with a hypothetical maximally decentralised system, there's always a centralised chokepoint where a specific organisation (including and perhaps especially, a state) that you wish to prove your identity to chooses to unconditionally accept records from the system.

[latchkey]

How is this any different than people choosing to accept (or not) payment in bitcoin?

[Oxidation]

Well, exactly.

But I would still say that in your original example, the use of blockchain is particularly unnecessary.

[latchkey]

Well... there is a distinction there... permissioned blockchain, no... "decentralized" bc, yes. All assuming that governments agree to acknowledge it, which, I agree, will likely never happen on a global scale. That said, other globally disruptive things have happened, like shorttermrentals and rideshare... so, who knows.

Imagine 1000 years from now and people are on mars... you think that everyone is going to be carrying around a paper passport book? It is going to look vastly different than it does today. I personally feel that it is important that the technology for things like this are experimented with now.