What about copper rounds, or uranium futures, or cell phone minutes? All seem to work nearly as well and have useful production purposes. I don't think gold is going anywhere for the reasons you cite, but there are alternatives today.
Cell phone minutes and uranium futures cannot.
By "copper rounds" do you mean ammunition? If so, then yes, they hold value and will last as least 20 years, or longer (corrosive ammunition from WWII is still usable).