> It seems pretty useless for spending on supplies and food if you ask me.

Seem pretty useful to me. At least historically, you can generally exchange gold for goods even in a total disaster scenario. You won't be weighing anything out or getting change, of course. You'll be seriously overpaying by the standards of a functioning economy. But nonetheless, you'll be able to engage in enough commerce to help you survive.

That said, I don't keep gold around. I do keep cash -- but if things have devolved to the point where cash isn't useful, then I'll have much larger problems than figuring out how to buy stuff.

You could carry some Goldbacks: https://www.goldback.com/