I think it will take something maybe years to eliminate fiat money because many people still very dependent on it but i think it will be eliminated still when everyone will be instructed to use blockchain technology.
I dont know why we should not eliminate fiat currency from our transactions. When we have one currency usable and acceptable all over the world and in our local markets then what is the benefit of fiat currency. I think that cryptocurrency is far better than fiat currency because of the wide range of use and acceptance. I dont need fiat currency in my future.