I think we need a comparison to see future trends:
Crypto:
+ Advantages: transparent, safe, decentralized, cheap transaction cost, high speed, no intermediaries required;
+ Disadvantage: requires modern equipment & internet. Legal issues that threaten the power of governments.
Fiat:
+ Advantages: Government issue & value guaranteed. Easily accessible to everyone.
+ Disadvantage: devaluation, lack of transparency, easy to be counterfeited.
As such, crypto will become a trend for users with conditions and in countries that are open to crypto. And fiat will continue to exist in developing countries and reach normal people, who don't have chance to use smart devices and internet.