Also "banking the unbanked": giving financial infrastructure to anyone with internet access, even if local banking infrastructure doesn't exist or isn't accessible.
Which is great when applied to rural areas of underdeveloped countries. But realistically it's more about financial infrastructure for criminals, outcasts, scammers and rich people in counties with strict financial controls
Stablecoins are interesting, but they're closer to company scrip than to decentralised currency. Anyway, stablecoins are apparently becoming important financial infrastructure, so that's something.
Bitcoin is completely useless as a currency since its value does not decline with time, thereby making it an investment vehicle instead of a currency. An asset can't be good at being both a medium of exchange and an investment. Only criminals use bitcoin as currency, and they do it because the alternative for them is moving cash around in suitcases.
Which is great when applied to rural areas of underdeveloped countries. But realistically it's more about financial infrastructure for criminals, outcasts, scammers and rich people in counties with strict financial controls