What do we think of a time that may come when the fate of human survival will depend only on using cryptocurrency for buying and selling, because mankind may soon find Fiat currency is obsolete or of no value in their current environment perhaps due to world earth crisis or pandemic or war .
Your opinion is valid!
During the time of war, there may not be any opportunity to operate a computer with one another, how much more buying items on any market places, whether physical with Fiats or buying online with cryptocurrency.
Again, despite the devastating conditions during the war and it's tension and apprehension, Fiats may still be useful in fact. there must be means of exchanges, probably fiats may be a better options in my opinion.