I think realistically that any dystopic post-aftermath of social breakdown would inevitably result in some persistence of order, perhaps in the form of integrative local entities, such as militias and technocrats.. and even a post-apocalypse, so long as humans survive and persist to greater/lesser in a return to medieval, albeit post-technologic, state.. I trust even then that gold and silver would still inevitably be accepted as a medium of exchange. It cannot just simply be aborted from the concept of exchange just because you don't like it or you don't feel you have a use for it. Gold and silver do not give a flying fishtank what you think, it merely "persists", historically entrusted by homo sapiens, regardless of your "modern" sentiment, as a marker to hold some degree of possession in exchange for some concept of labor. But whu-do-I know, I just swing at moving objects.. like fishtanks!