There is nowhere near enough gold to back all the world's currency. It might be a good idea to come up with a basket of asssets, which could collectively back all the world's currency, but it's doubtful that that would be practical.
The answer, for individuals, is to acquire hard assets on their own, if they see a need to do so.
“There is nowhere near enough gold to back all the world’s currency.”
I don’t know about the rest of the world, but there is supposedly less than $800B of US paper currency in circulation. Most of the money in the world is just numbers in computers. Fort Knox holds about $200B in gold at today’s prices. I don’t know how much the US has in gold in other locations, but clearly US paper currency in circulation could not be redeemed for gold without gold going to $6,000 an ounce.