Regarding digital money, time will tell how solid the current cryptocurrencies are. But one major thing it has going for it is decentralization, which actually gives it a leg up on gold, or gold-backed paper. Even gold is a symbolic store of value, of course - what I'm saying is that in the case of money the qualities that make it valuable (or not so valuable) aren't arbitrary; societies select for these qualities before agreeing to a common medium of exchange. Just because something is conceptual doesn't make its properties arbitrary; that the Venezuelan Bolivar doesn't equal the US Dollar isn't a matter of mass (dis)belief, but rather one of fundamental differences. We could all suddenly stop believing in a currency but that wouldn't circumvent the need for some kind of currency, as direct trade is impractical outside of tiny communities. So, money is a naturally occurring need, and the properties that make it good or bad are consistent across time and culture.

Gender identity truly is a fugazi though. I think "non-naturally occurring money"--basically everything from WWI to Bitcoin--is analogous with gender identity ideology.