If you're willing to admit a central authority to authenticate who can and cannot vote, cryptocurrency becomes easy.

Really bitcoin is fundamentally trying to solve the problem that its impossible to tell who is a "real" person on the internet. If you dont have that problem everything is trivial.

So what you're saying is, bitcoin was always useless in sufficiently advanced society, like mine, where I routinely verify my identity online through my bank?

Interestingly, the original bitcoin white-paper had a motivating example that basically amounted to side-stepping banks, because banks do not provide fully non-reversible transactions. In essence, bitcoin was a technological solution to a problem which would have been solved more elegantly by changing financial laws, and requiring banks to offer non-reversible transactions. (the problem with that is obviously that it could be used for fraud, but then you get into the whole debate about freedom vs protection)

> In essence, bitcoin was a technological solution to a problem which would have been solved more elegantly by changing financial laws, and requiring banks to offer non-reversible transactions.

Ahh, this may explain why I don't see how cryptocurrency is a good thing. I consider the fact that banks do not allow fully non-reversible transactions as a very strongly desirable feature, not a bug to be done away with.

And I think this is a very valid viewpoint. Clearly, many people think the same, otherwise we'd already have non-reversible transactions in the conventional banking system.

I mean, yes. If you read the bitcoin paper it very clearly talks about what problems it is trying to solve, so this shouldn't come as a surprise.

Whether or not it is useless really depends how much you value independence from a central authority (i was originally going to say anonoyminity, but if you only care about anonoyminity, digicash is a much better solution than bitcoin)

Indeed, for more nuance here's a full explanation of the problem being dealt with by various Proof of Whatever algorithms: https://en.wikipedia.org/wiki/Sybil_attack

They always rely on scarcity of something: scarcity of processing power, scarcity of being on the ledger of the blockchain and owning an amount of currency, scarcity of hard disk space, etc.