In my opinion in the future, the currency will simply become digital, for the reason that most countries are developing their stablecoins instead of joining efforts and creating an international cryptocurrency!
but if I think that in the future the fiat currency will not be replaced, because fiat currency is very important for the country because it has become a symbol of the country too. and even though there are already lots of digital currencies but they cannot replace paper currency or fiat
Yes definitely fiat currencies are very necessary in this world.Each and every person uses fiat currencies for day to day transactions.Fiat currency is accepted internationally.Banks and governments support fiat currency because it is centralised.Fiat currency can be used anywhere and anytime unlike cryptocurrencies which require internet connection to get operated.Cryptos are also decentralised and risky as they can get hacked too.