But later on in France, these authorities became untruthful and start to dilute the gold in the coins, and John Law even came up with the idea of fiat money that is backed by shares (Mississippi bubble), thus sank the credit worthiness of fiat money, and failed. But since then fiat money started to be backed by some complex securities that is totally out of understanding of average Joe, and became a supply/demand game
As I know it, it was not John Law's fault, or the failure of the principle behind his system. Its collapse was due to heavy abuse of the system by the Crown, which thought they found an endless fountain of wealth