Bitcoin will never replace fiat cash. A coin everyone mints at the same rate will. It will also replace bitcoin and all of the shitcoins.
Mark my words.
Bitcoin runs off the fumes of fiat.
we've been through a lot of topics like this...
Bitcoin cannot replace fiat currency because fiat comes entirely from a country. currently, there are thousands of fiat currencies from all countries of the world. replace fiat means to replace a national currency. Bitcoin will continue to move alongside fiat.