Bitcoin will stat on top of all crypto currencies but this does not mean that crypto will remain forever. Who knows after 100 yeas there might be no signs of crypto currencies and bitcoins.
How can you say that?
I am not saying that it is impossible, it is possible but saying that there will be no signs of cryptocurrencies in the future? I think that is impossible. One of the greatest technology Bitcoin has is the Blockchain and a lot of people are speculating that it will be widely used in the future and not only in the market we are used to.