Does it make sense to believe that Bitcoin could one day be replaced by another cryptocurrency, that is, a cryptocurrency that really does make Bitcoin obsolete?
I personally believe that if some cryptocurrency overtakes BTC in future, it will be Ethereum. As the majority of ICOs are running over ethereum blockchain and success of few of them will have a major impact on ethereum. It will be difficult to predict that BTC will be obsolete by that overtake or not, I don't see any valid reason for BTC going obsolete as long as cryptos and up and running.