I think fiat cannot be replaced with crypto and that's the reality.Right now we see that digital money is important because of the virus but time will come when it's over, everything will return to normal and we will use cash again. I agree if fiat collaborates with crypto for a better future in financial system, that's great.
There are news already about companies like visa and mastercard working on own crypto-fiat system, moreover kraken has started to work with several banks already - its happening