Since bitcoin is known to be the father of all crypto currencies , it wouldn't so hard for it to reach what fiat has. It is already being compared to fiat which is an advantage for most of us users. Bitcoin is being valued and used same as the function of fiat bit we can't deny the fact that it can replace the virtual money.
BTC is very "young" and it will probably be in a position to replace paper money in a few decades.
The adoption percentage is still too low right now.