soon enough, we'll have little or no need for Fiat currency, currently in my country, a good number of persons purchase things with Bitcoin and other crypto currency, I know they're disadvantages to it too though but, there's nothing with an advantage that doesn't have it's disadvantage.
The good thing here though is the fact that it's advantage beats the disadvantage by a good number.
If this is done in my country, then it is a violation of the law. My country has a law that the legal means of transaction is the rupiah and other currencies that have been recognized throughout the world. Because currently my country only recognizes Bitcoin and crypto as commodities. Although I also know there is a possibility that some people have done that with the deals and risks they have known before. Although it would violate the provisions of the applicable law. This is why my state started going to create CBDC, and the whitepaper is ready a few month ago.