Of course gold is fungible. You're trying to apply externalities such as government that are irrelevant to the definition at hand. Yes, the govt can make a law outlawing oxygen too. Does it mean oxygen is not fungible now? No. The periodic table does not recognize the authority of a man claiming to be god (govt).
Breathing is decentralized. Mediums-of-exchange and stores-of-value are not, as they depend on the consensus CONFIDENCE of even a significant minority of the population.
Gold is a highly inferior medium-of-exchange. It's store-of-value function is suffering from the changes in technology and surveillance which make it nearly impossible to transport it without suffering extreme risk. Used to be you could hop on a boat and take your gold with you (with sufficient hired security). Now you need permission from government to do it, else you're at extreme risk of being thrown in some sort of Guantanamo Bay prison.
Fungibility is really not the relevant FUD any more. The issue is that no currency nor store-of-value operates outside of government. And thus cryptocurrency at least offers the ability to do jurisdictional arbitrage. This will work until the NWO world goverment is formed (because the Zionists want us to subvert the nation-states!). I told all of you that the Zionists created Bitcoin in order to force the nation-states to demand a world government because Bitcoin subsumes the authority of any one grouping of nation-states.
Bitcoin is a bottom-up subterfuge of sovereignty (both nation-state and personal sovereignty are eventually destroyed at their end game).
By not investing in crypto, you're missing out on the massive transformation of world from nation-states to a NWO world government model. You can't stop this outcome with your silly precious metals fetish. The elite have been quoted as stating,
"we will burn the fingertips of the goldbugs up to their armpits". You gonna learn the hard way @roach.