Some day I sure bitcoin can replace fiat, we know fiat is is not relevant to the economy and free trade.
But it is a basic true that bitcoin cannot replace fiat, fiat has been and will forever be the way to exchange money between people directly, bitcoin appeared first to make exchanging money over the internet much easier so it has always been related to the internet but if the internet goes down so is the bitcoin and then what is the thing that is goanna run the economy for sure it is the fiat money.
i agree. physical money is still the way most transactions are normally done every single day. it's government ran. it's accessible to most people. it doesn't need online connection. bitcoin is good for transferring money and doing online transactions but it still is dependent on whether there is online access. compared to fiat, which as you've said is how most transactions were done, bitcoin would require a lot more to be fully accepted and i think with how things are going now, fiat would still be the major form of currency that we will all have even in the future