Investing in gold as a hedge for the collapse of society is imo a really piss-poor idea. Either invest in stuff you can use (i.e. food) or stuff that will be demand (Ham radios, firearms). Gold is just not going to be the future medium of currency there isn't enough of it in practical sized values.
[1]: https://en.wikipedia.org/wiki/History_of_money#Overview
Ham radio is only useful if you can power it and find someone else with one who can also power it, my guess not enough people will have them to be useful. firearms are only useful if you have ammo - while you can make bullets and black power it is hard to say if it is worth it. I doubt there will be much firearm trade unless there is an ammo manufacturing (no longer society collapse - though a much more likely scenereo) - people who have ammo will keep the guns that go with it.
I'm not disagreeing that there are plenty of things other than gold to hold onto. However gold is still a reasonable choice for post disaster trade for the same reasons society settled on it in the first place. (note that society also used copper and silver for trade)
Roman currency (both the coinage and the numeric value promixal to goods) lasted for years after the empire fell. It was just easier to use that relative value, and rely on local credit
> "society will have broken down far enough that even the gold will be relatively worthless and the predominant goods of choice will be cans of dog food and beans.
it absolutely was peaceful, especially in those two countries.
Again, yes, it was peaceful BETWEEN the US ans UK, but your thesis that the primary global currency can collapse peacefully without a catastrophic global crisis is... well, picking the transition of the Pound to make that point is not a choice I would have gone with.