Maybe is impossible cryptocurrency could replace fiat, many people still do not know how cryptocurrency and bitcoin are working, how to make payment with cryptocurrency and how price is speculative.
well, so many considerations before cryptocurrency replaces fiat. even the public's trust is still so small about crypto. well, in my place, many thought that crypto was related to gambling, and could only be used as that. well, i think before replacing fiat, maybe a lot of people have to learn about this technology.