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.
fiat and crypto currencies each have different segments, each of which has crypto deficiencies and strengths which are more dominant in unlimited country exchanges and with an unlimited number, whereas fiat is more dominant in domestic exchanges where the market system is still traditional, so the two are mutually support and can walk together.