It used to be a joke of sorts ...
It’s always been the root currency along with beans.
Beans and Bullets.
Study the human behaviors, the starvation, the ensuing savagery of for example the war in Bosnia-Herzegovina 1992.
Under such conditions, Gold and Jewelry don’t matter.
The only thing that matters to survival under such conditions are BEANS and BULLETS.
IMHO, if SHTF, it will be worth more than gold, possibly a price above rubies..