You can pay taxes in crypto in several states.
https://www.forbes.com/sites/kellyphillipserb/2018/11/26/ohi...
https://www.forbes.com/sites/kellyphillipserb/2018/11/26/ohi...
Of course, the theory may well be wrong, as evidenced by e.g. Somali shilling still being in use, even though there's no government backing it in any practical sense for decades.
According to what I read the "stability" prior to the central bank was a result of an equilibrium between the value of a note and the value of the paper it was printed on. Since there wasn't a central government printing money, it didn't decline further, but tying up $100 in paper to represent $100 seems pretty suboptimal.