IMHO there are a number of threads to the augment as to the value of gold or PMs
It is a commodity that can be traded/gambled upon like many others as such it's value or benefit to the world is irrelevant as long as the price goes up and down for whatever reason then people can trade and make money, to them it's place in the world does not matter
As to the augment as to who would buy it if the paper money system goes to dust, if there is no paper money people will need another system to continue to function and PMs have always been there to do this.
At one time even salt was a form of currency. PMs will provide this function because it is always in limited supply so will be a stable form of currency in a time of disaster
If the world went to a PMs standard the power of the CBs would disappear overnight, they would cease to exist. Imagine no CBs and the big money people of the world would have no more power over the worlds economic systems
So if there is the slightest chance that this would happen don't you think that they would do all in their power to make sure it never happened, so you get the stories and manipulation.
There is not enough PMs in the world to replace our paper money system but some sort of joint system could still come in with a bag of currencies backed by gold or silver to use as a standard, such a system would have bankers dropping like flies out of whatever window they could find
