I think cryptos are just a different type of currency: they don't have any redeeming features unless, as caffeineaddict implied, you are purchasing illegal products. They are based on cryptography, and therefore are obscure and to me, somewhat nonsensical. As long as your normal money is accepted, whey go to the trouble of cryptocurrencies? If someone wants to share their opinions or disagrees with me, then i'm all ears.
One time I looked into bitcoin mining as a source of income since I don't have all the money in the world, and it's incredibly expensive and probably not worth your time unless you want to treat it like a full time job. Doing it profitably will undoubtedly raise your energy bills.