For me fiat is almost vanish from the world now, as there people use only digital currency the most as compare to fiat, in some place people use fiat but only under some specific circumstances otherwise as per need of day fiat and cash has lost their value and digital currency took important place in market.
Really? Then tell me which country are already "fully" developed by digital currency where they don't want to use flat anymore. You can't forget flat as your main payment source and do you ever think about those 60y.o people that probably they don't know about crypto and uses flat as their currency. Don't be ego.