As the market becomes more saturated more users are turning towards the top two crypto coins and those who had already invested into other altcoins have starting shifting their funds towards Bitcoin and Ethereum as other altcoins have failed to capitalize the market. If this continues then how will altcoin survive? is it just the matter of time or something which altcoins need to work on by working on the missing link.
Bitcoin is the main pillar of this market and altcoins are its smallest. BTC can not continue without altcoins, they are without BTC.
The market is open to everyone and anyone can create altcoins as they wish. Giving big value to eth and btc does not mean that it is not given to others. Maybe just a little less. While btc and eth are the only ones in the market, make sure the market will not get that much attention.