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.