That will never gonna happen, crypto replacing fiat money is just a dream and we have to face the reality that it is very impossible for that to happen. Fiat is what we use for so many years and it is important for on everybody else's lives. The fact that crypto is only use with the help of the internet and you we can only do transactions online but not all people has an access through the internet that is why Fiat is important to many people. Crypto will exist together with Fiat but it never replace it.