I'm not sure that Bitcoin will replace fiat. I do not see any sense in it. Bitcoin has already taken its place in the economy and in the life of users. Why do we need to Bitcoin replaced the dollar
Bitcoin is supporting our digital financial but not for the our real financial. bitcoin is not taking the place of fiat. and bitcoin still have a lot of the home work with the government authorities about to the legal statue.
yes currently its look like impossible but i think it is possible but late in future not so early. when all people will accept bitcoin and will start bitcoin instead of fiat. then fiat will become useless and bitcoin will surely take its place.
Fiat becomes useless? I dont think soo and government wont let this thing to happen as long they are here they wont allow such thing as bitcoin a decentralized would take the place of fiat. No matter how bitcoin would progress fiat would still remain strong no matter what.