I also seen the progress of crypto but i never seen a reason or a way that it will replace fiat, if there will be a new development in the future with some more adoption maybe it will replace fiat, but for now it is still hard because not all of us who are living in different country knows about crypto, many more people also did not know about crypto specially to those who are in a poor status who doesn't know about digital transactions and even internet or using new gadgets.