Total removal of fiat from the society will do more harm than good.
No matter the level of technological development, not everyone will be able to embrace cashless transactions. And also, most services need to be paid in cash.
That is really true. It will not be a problem only to those who are people depending on fiat money but also to us. Because fore example, we will go somewhere where the internet connection is very poor or the vendors don't have smart phones to use so they can access the internet, we cannot buy right because there's no fiat money. How can we pay if it happens that there will be no internet connection? What will also happen to people who are poor if cash will be extinct?