completely unusable as a currency, even maximalists cant seriously tell people to use it as such. "cryptocurrency" at this point means less useful than any currency in any mmo
Bitcoin totally failed as a currency, but it's still something. I'm not necessarily arguing Bitcoin is useful or valuable period, but the issue you refer to is more with the "cryptocurrency" name and public conception that that's what all this technology is. The core idea is reliable, secure decentralization and the things it can enable.
Coins that support smart contracts show that "cryptocurrency" isn't a great term. Even if you never try to use ether as a currency (and indeed, most people don't), Ethereum can and does still do lots of things completely unrelated to finance in any way, with ether just serving as computational fuel.
The interesting part is fully trustless peer-to-peer networks, not e-currencies. E-currencies are just an example of one thing you can run atop such a network protocol. They've already existed to some extent for a long time via protocols like BitTorrent, and these just expand on those ideas.
Some people see it that way. And it probably does serve that purpose to some extent in areas with very unstable governments, like some developing countries. But I'm doubtful that by the year 2121 Bitcoin or any other cryptocurrency will have kept the US government "in check" in any way. It's not impossible, but I'd heavily bet against it.
They may very well make/adopt some cryptocurrency as the new primary fiat by then, but I kind of see the idea of Bitcoin keeping the US government in check similarly to the idea of gun ownership keeping the US government in check.
Out of curiosity, can you describe an example of how it could potentially serve such a purpose, even in a hypothetical contrived scenario?
I recently needed to buy something from a merchant, who was not able to acquire a traditional credit card merchant account, or a business checking account. I had three options to pay to that merchant: cash in the envelope, money order, bitcoin (merchant also run a promotion for bitcoin method of payment, discounting the total of the order by 20% when paid by bitcoin).
Bitcoin turned out the best option out of these three.
I'm quite skeptical of Bitcoin in general but I can't deny that Lightning Network has really started to take off as a means of payment, it's even a common sight in El Salvador to see Bitcoin accepted through LN, where transaction costs are in the fraction of a cent.
Coins that support smart contracts show that "cryptocurrency" isn't a great term. Even if you never try to use ether as a currency (and indeed, most people don't), Ethereum can and does still do lots of things completely unrelated to finance in any way, with ether just serving as computational fuel.
The interesting part is fully trustless peer-to-peer networks, not e-currencies. E-currencies are just an example of one thing you can run atop such a network protocol. They've already existed to some extent for a long time via protocols like BitTorrent, and these just expand on those ideas.