I see bitcoin and fiat to be the perfect compliments of each other as the can be used interchangeably whenever we want to cut down on fees when trying to make a transaction so both will co-exist
yeah , and also there is another reason to not to replace fiat is use of fiat in real world .
Because the fiat and Bitcoin ( online ) are useful but fiat works as a important role in practical world and in practical world everyone looking for fiat only so it is about not possibly to replace fiat by Bitcoin .