Why can't we just use other currencies?

If you haven’t checked out the “why can’t you use gold as money” thread, please do. I don’t believe the question of why gold can’t be used as money has been adequately answered. It looks like there may not be as many reasons as people have suggested.

https://forum.freecapitalists.org/t/why-cant-you-use-gold-as-money/19865