Gold cannot be used as money in any meaningful way in todays economy unless its a backing to a cryptocurrency vehicle.. im which case you will lose the backing sooner or later just like we did in the 70s with fiat.
Germans use cash for almost everything and it didn't cause them to revert to the stone age. There is nothing preventing the cash from being replaced by physical gold and silver (and maybe copper) coins utilized in it's native form. Assuming cryptocurrency doesn't implode from the winner take all paradigm, it's entirely plausible every form of currency dies except physical gold and silver coins + Bitcoin for digital transations.
It doesn't really have to be one or the other. The market will demand some form of physical cash to exist and will demand some type of digital transfer mechanism to exist as well. Physical BTC bearer bonds that are never actually checked or exposed to the system to determine if they're valid are kind of a dumb idea as a cash replacement and precious metals would probably easily defeat that use case.
You also have the problem that physical BTC bearer bonds would be fee-free, hence maybe seeing a huge uptick in usage for a limited load system and undermine the security model of Bitcoin itself. Imagine BTC transactions costing $100 each so people all decide to use physical BTC bearer bonds to skirt this drawback, or even mail or UPS them to each other and bypass the blockchain altogether. People buy thousands of dollars in metals using the mail, so why not?
The blockchain of metals is two neutron stars colliding to create a permanent immutable ledger of supply for your local closed ecosystem. It requires no overhead to exist or verify transactions, while also having unlimited TPS, making it obvious in having some use case as currency in all but the most dystopian locked in the matrix systems (which anonymint seems to refer to as progress).
The Satoshi quote of "no free lunch" is kind of erroneous as both fiat and Bitcoin require overhead just to exist at all while gold and silver do not. This is probably the biggest Satoshi red herring that exists. Nobody is forcing you to pay to store it in someone else's vault. You cannot use the word "ideal money" to describe something that requires overhead just to exist when there are alternatives that don't.
Paper is always going to be Keynesian by definition, and even if you could somehow overcome that logic and eliminate the horde of parasitic technocrats, you'd still have to constantly reprint the bills, and using metal coins would eventually just be sending you back to gold and silver anyway.