Do you think Bitcoin will remain the most dominant coin both short and long term? Even though it does not remain the most dominant coin, this will not be the same as saying that Bitcoin wont exist long term.
Until unless all altcoins are valued in bitcoin i dont think that any other coin take over Bitcoin. Even ETH have tried so many times but still btc has its own value as it is not controlled by anyone this is the main success of btc. ETH is controlled by developer and even he is holding the major share of coin so always it will be afraid that if he sold everything in the market and left over the project then who will take care of ETH and its network. So i think Bitcoin will always dominate the crypto world until some other coin come like btc or the founder of btc dont come up with new coin.