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survival will depend only on using cryptocurrency for buying and selling, because mankind may soon find Fiat currency is obsolete or of no value in their current environment perhaps due to world earth crisis or pandemic or war .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!
I believe that cryptocurrency will be a significant aspect of human life in the future, but as a sole means of survival, it is still an unrealistic concept. Honestly speaking, war, global catastrophes, or pandemics can devalue fiat currency, but whether they will render it useless is uncertain.
Crypto can indeed be a boundary-less means of exchange, a system that is decentralized, and a safe store of value. And then when old money becomes worthless one day in the future, humans will of course seek elsewhere, and going to crypto would be no further out of place. Whether it will be wholly compulsory, however, lies in the hands of governments and the global financial system.
My take is that crypto and fiat will coexist but, in extreme cases, crypto would certainly be a particularly significant aspect of individuals' survival.