Cryptocurrency will not replace the fiat money because the fiat money are backed and supported by the government and that is the reason why we can't expected that cryoptocurrency will just replace the fiat money because it is not also a stable currency since its market is so volatile and not the best for pricing.
I completely agree with the statement. I think both fiat money and cryptocurrency will just co-exist, and one will not replace another. The one is as important as the other to the people who makes use of it, especially for a living. If cryptocurrencies will replace fiat money, its value will never be stable for the reason that the market will always have a change in the demand. This will definitely cause trouble for a country's economy, if in case it happens.