In my opinion As long as fiat money still serves as a medium of exchange, it will always be needed by the people of today and therefore it will always have a function as an asset to all of us. although the best value-keeping asset is gold but even though gold is quite liquid, it is no longer money that serves as an intermediary.
Bitcoin and fiat currency made a balance in our society. Bitcoin is a digital currency which guide us towards a advance society. Sometimes fiat currency disappoint us like, Fiat currency is a physical form of currency so many time its duplicate are made by criminal minded which affect our society and our country economy too. Using of fiat currency is not always safe and easy to use. Like i said fiat is not fall always. It is a usefull asset in where no Internet or electricity connection present. 