...if they are to be used for REAL WORLD money transfer and usage!!! Simply the fact that they operate with a limited supply, makes it so... Do you know any fiat-currencies with a limited money supply? No, because that would be just too stupid, right? Well guess what, that's what 99% of the crypto"currencies" use.
A friend of mine has written a piece about how an alternative model may look. Help spread the idea.
https://medium.com/@svein2122/work-backed-blockchain-money-and-decentralised-money-creation-e76886b90c3b