In my opinion. until any time the fiat currency will be needed and used throughout the world. technological advances in the financial sector will not affect the existence of fiat currencies. Digital currency is used to facilitate everyone in choosing transaction tools so that our work will be easier. and fiat currency is used for people who do not have a digital currency.
I think the answer is to ask yourself, are you still using fiat to buy something? I think most or even all bitcoin users must still rely on fiat to pay for their daily needs, you are right that technological developments will not change anything on fiat as the main currency
I like your answer. Really, look around - ALL fellows, who are the crypto traders and investors are using traditional money (cash and credit cards) actively. We cannot live without fiat ever.