fiat currencies still necessary in every country because people still use fiat to buy anything. but fiat currency slowly has to turn into digital payment because we see some apps offering us to deposit some amount of money to them so we can use it to pay for something we buy without using fiat. and I think in the future, the fiat will still exist but there are many options of the payment which comes from the digital payment like I said.
Also fiat also involve with country's development. If you're thinking to replace fiat with bitcoin then its impossible.
Government can still use cryptocurrencies to replace the fiat, but we are talking about a lot of years from now, maybe a century or a millennium, we don't know. What we all know is that the future is pointing towards to these technologies started by the solution of double spending made by Satoshi Nakamoto in the past of cryptocurrencies in which is called the Blockchain.
Fiat currencies are still necessary in the world, there are no other way to pay now without these fiats. I mean yes, you have your mobile applications or cards;ATMs or Credits but I don't think they would be able to give it a load without fiat. Without fiat, we will still be using other things we can trade with the same value, and that is bad.
Yes of course. Fiat money is very necessary in the world. No matter how cryptocurrency become popular and become so useful it couldnt totally replace the fiat money. Fiat money couldnt totally be eliminated just because something new came up.