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.
Before there there was no internet but later internet reached at most of the rular areas and people were started using it. Now a days u can buy sell crypto through mobile and mobile companies provide internet facility.
In this time there is no possibility that we eliminate fiat currency from the system because it is owned by the government and cryptocurrency is not legalized by many governments yet. It will take long time that we will see cryptocurrency taking over the whole currency (fiat and paper) market in the world. But hope that we would need for fiat in the future.