I don't think that anything should replace Bitcoin. Bitcoin is the leader of crypto and the flagman for the whole industry IMO.
I do not think there is any coin to replace the BTC in the future, I believe the BTC is the king of the Crypto market forever, even if the market is falling, BTC is still a coin occupied. By the end of 2018, BTC prices will rise more than $ 50,000. I believe this will happen.
What can really beat bitcoin when all of the altcoin world depends on this single digital asset? It is pretty fine with me if no one is going to believe in my words but this does not change the truth and the simple plus most obvious truth of digital market is that it entirely depends on bitcoin. Like we have recently seen, when bitcoin was at its peak, the market cap was also at its peak and most altcoins were doing the same.
I actually believe on you since i have the same faith. My trust is going to bitcoin when this crypto goes very strong and not anything can replace bitcoin from the strongest crypto. I dont ever support any other altcoin will defeat bitcoin.