Cryptocurrency is present since 2009, but still, even after a decade, there are many places across the world where it's not accepted like fiat is. I agree that every year the number of crypto users are increasing, but even then, there are countries where people are not allowed to freely use crypto, or even worse, it's completely banned to use, hodl, trade, or anything that has to do with cryptocurrencies. And the places where it is allowed, there aren't many applications for the virtual currency.
Anything can be bought with fiat currencies, but when it comes to crypto, there are just a limited number of uses, the basic ones being trade and hodl. There are applications and websites allowing crypto to be a mode of payment, but the number of them having this option is not enough.
So, for now, I guess it is a future currency. But over the next decade, it'll be widely used. Hopefully.