The European Parliaments Committee on Economic and Monetary Affairs (ECON) has come up with a report on cryptocurrency entitled Virtual currencies and central banks monetary policy: challenges ahead. The finding of reports shows that cryptocurrency will not replace fiat currency, even in the long term.
https://bit.ly/2NeLgLrCrypto replaces the fiat is not something that crypto users want. The better is crypto and fiat running side by side. All have advantages and disadvantages. Will complement each other. No need to eliminate each other. This is not desirable.