bitcoin has many advantages
fiat has many advantages
That's why I don't see any reason to make comparisons.
for example:
fiat is recognized by governments which allows it to be used in countries, everything you buy uses fiat, people receive a salary using fiat, but there are maximum values for walking on the street with fiat, something that does not happen with bitcoin where the person can be their own bank
All these advantages will be happening to bitcoin soon if the massive adoption will continue. It may not replace fiat, but its a good alternative for fiat in the future. For now, the best advantage of bitcoin is to have it for financial freedom. And this is rare to happen in fiat, as inflation continue to depreciate the value of fiat. And while fiat is closely monitored by the government, with bitcoin you can have limitless opportunities without the authority monitoring it.
I will further tell in this case that it was also a time when gold was also a currency being used by all over the world and then with the introduction of fiat many people found it strange to use and some opposed it but then a time came when fiat was the only currency of the world. Now another transition may occur between fiat and bitcoin. We will enter in another time when people all over the world will use bitcoin as their currency.