You know fiat and cryptocurrency is an asset they have both advantages and disadvantages so they should co-exist no one will replace another. Yes, cryptocurrency has more potential and better than fiat but I am seeing in the distant future fiat will still exist and it is pretty needed in our daily lives. If no fiat there will be no stablecoins that are backed with dollars.
they will not completely replace each other, but I think that in the future, cryptocurrency will be a more popular tool to use than fiat money. obviously it is more convenient
There was only a free cryptos that can be used as universal money while so many cryptos can be categorized as security which means you can't use such security coin as a payment system. It's not all of cryptos have been filling all of the requirements to be used as a universal currency or a payment system.