It's useful for cross-country transfers of money, and in-country if the alternative would be very annoying (or you just happen to have some cryptocurrency around and not regular money). I do use it for that and I've found it useful. The biggest downside in my experience has not been all the abstract figures and numbers and stories floating around, but the exchanges. Turning cryptocurrencies back into regular money is very annoying and the US ones are even very shady (locking your money in, etc). It's what's keeping it inside of the fringes for me.