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.
Bitcoins is very profitable now a days due to its price that goes down in the market so everyone will have the chance to invest and ethereum price is tether to bitcoins, so always remember that most of the altcoins today that is being released in the market are tether to ethereum so obviously, every cryptocurrency is being affected when bitcoins price is decreasing.