i wonder if gold/silver is used if a natural disaster occurs. do people in syria now or people in christchurch (after the earthquake) use gold/silver or still use fiat? how about greece during the financial crisis? there was a shortage of fiat. you never hear about those things.
Greece never really went through a crisis - it was the media that hyped it into that. The shortage of fiat in greece was only for 14 days. People did not die of hunger in that time, so it wasn't really a problem.
why you think gold not worth anything when disaster came? example in conflict zone atm precious metals(not only gold) still used as medium of exchange. When internet goes down in the entire world (gold already pass through that era) yes it will be bigger problem, but who will stand as medium of exchange when that moment come? is it paper money, gold or bitcoin?
Gold could be used during the medieval ages as a form of payment - today it can't - in the future it can't. It's so easy to make fake looking Gold, that it would be impossible for the public to determine if it was real or not.
If the entire world went into massive crisis, with no internet, no fuel, shortage of food etc, I bet you that food/medicine will be the primary currency. I will trade you 2tons of gold for 1kg of food because my family is starving.