Cryptocurrency is the future of all payment method due to the decentralized nature which grants financial freedom and power to the people. However, for it to replace cash or the Fiat, it will take years of awareness creation. Up to date, some people do not have access to internet whereas others do not know how to access it.
Cryptocurrency is the future but not all the payment. Just think of isolated areas in different countries that does not know about the idea of internet? even we are on technological age we cannot deny the fact that there are still some group of people who does not welcome the uses of technology such as tribes for example Africa and Asian countries who are known as a very cultured countries. It would take a long long time for fiat to be a cryptocurrency.