I don't think that Bitcoin can be replaced with any altcoin because it's really the first and the strongest crypto currency so far. I don't see any potential in any other coin to replace Bitcoin in the next few years at least. Some people were saying before that ethereum can replace Bitcoin in some point in the future but I don't think that's gonna happen.
At the moment, none of the existing altcoins can replace Bitcoin. This can happen if something happens to the Bitcoin ecosystem, but so far everything is working well.