The big question is do we have any government now that can implement this, this is not easy, you need all people educated and there are areas that can be transacted with fiat only because not all part of any country has the features of a city, only a highly industrialized country can do this.
Yes, we have. The government in every country has the capability to do it. If it will be implemented in a certain nation, I think even in rural areas it will be issued. Fiat is part of every people's daily use, and if crypto will replace fiat then there is no chance for the countryside to stay using fiat even if crypto is already implemented to use in their daily life.
I have a mixed feelings about them making the current fiat currency to be replaced by cryptos. People in rural areas might not get used to it that easily even they're taught on how to use it. Problems could occur like a accidentally spent coins in a transaction wherein they can't return back the spent coins once it has been confirmed in a blockchain like Bitcoin.