Gold definitely can't be used as a currency, not right now anyway and we are not gold backed fiats anywhere in the world as far as I know which all combine makes it impossible for gold to be used.

But, fiat loses its value due to inflation as well, and this isn't like a single fiat, every single fiat loses its value, some more than others but they all do. That means we need something that can store value as good as gold, but can be easily spent as easy as fiat, what do we have like that? Hmm... Bitcoin? I think so, I believe that I can easily invest into bitcoin, anytime I can spend it then I can, we do need more adoption and more places that accepts it, but all in all I can say that it is the ideal asset right now.