There are so many possibilities in here if the cryptocurrency will remove or replaced FIAT currency there are some people that doesn't want to use it because they don't know. There are some good deeds it can provide like the faster transactions to any people who use it. But before that happen for sure it will gonna be world discuss.
There will be a huge debate about this thing for sure, and I know this will not happen easily. I actually don't see cryptos to replace fiat, if that is the case cryptos will become more centralize so for me its not a good idea to replace fiat. Better to make a healthy competition with it and let people decide on what to use base on their liquidity.