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.
It seems to me that cryptocurrencies were created for this purpose. But when this will happen now of course is unknown. Think we will be enough a couple of years to understand what eventually will happen