Of course it will take time but I think it will be as altcoin as bitcoin.
There will be even more than one because the functionality of the banks will be reduced and such digital money will be valued.
I think nothing can surpass to bitcoin because it is the reason of the beginning and it is the mother of crypto. In it's continuously existing no one can replace or leading to it because I think most other coins are only base and depends on the movement of bitcoin system. Even if how many years will goes by I believe btc will still stand number 1 leading crypto currencies for all time.