it could happen because along with the times and technology that will grow very rapidly but of course it needs a process and a long and difficult time of course
I think that fiat will not be able to completely disappear even in the distant future. Many people love to diversify their funds and they will still hold some of the money in the form of paper money.
fiat money or local money isnt really an investment imo and you cant say that you will diversify your funds with fiats because i think that is unsual . fiats are currency and not an assets while crypto are the real asset and can also be used as a currency at the same time therfor they are more apropriate when you say diversifying your investment . meanwhile , i dont also think that fiats can replace cryptos because fiats will be the one that is more easier to use compared to any other e currencies as they are more complex .