How long do you think will the cryptocurrency be popular? Does she substitution the usual fiat money? How many years will pass before this?
Strictly speaking, crypto is popular only among a limited number of users (some say like 15-20 million), and all other billions of people are simply unaware of it.
So partly because of the reason stated above cryptocurrencies will not replace fiats in the in foreseeable future, unless something really extraordinary happens.