Any currency needs a sense of scarcity. Rare metal standards achieve that. Even the current Reserve standard has a “sense” of scarcity, even though there is fluidity in supply.
Cryptocurrency is standardized by the amount of electrons that can be dedicated to establishing it. There is hardly a scarcity of electrons on the internet.
Not necessarily scarcity, but stability in the rate of generation which is just about perfect for gold, silver and a few other metals in that they are increased in availability at approximately average 1.5% per year.
The only times they have been “disrupted” per say is when large volumes have come to developed economies unexpectedly, like Spain’s removal of large looted volumes from the new world or the gold rushes of the west US.
At the average rate the economic process can carry on at reasonable growth rates. People and business can still expand, but risk is better managed when capital isn’t able to be loaned with no underlying limit as it is with money based literally on debt.