From what I have seen so far in this forum and other crypto platforms, most of us want fiat eliminated. But let us not forget that there are still situations whereby we can't use crypto except fiat like in rural places without computers or even internet facilities.
I think as of now, cryptocurrency still has no chance to overpower fiat. Still people believe on the capacity of bitcoin but dominating fiat would not be possible as of now. I think if that will happen, I would not be able to witness it because that will take too much time to take place. There are many factors to consider and a decade or two will not be enough.
We do not have to compare it and cryptocurrency has no such target to replace fiat currency but is only to help us out using the easiest features for frictionless transactions etc. Fiat currency could only be replaced by crypto if government of a country announces it just like Japan where crypto currencies are rocking and many several countries where it is using besides their fiat currencies.