I think that ethereum will grow for the simple reason that it is the blockchain where there are a lot of developer (along with bitcoin) so it is difficult for these developers to start learning a new programming language and developers make the ecosystem.
Ethereum is known by lots of people and it's a great one to be the next big thing on the market by surpassing bitcoin. Bitcoin will be surpassed by ethereum and this is not that far away from now on.
I will agree that ethereum will also grow like bitcoin ,that if bitcoin will be fading in the crypto market ,there are also other altcoins that are also growing like ripple,litecoin,EOS ,Tron etc. but as of now bitcoin is much popular among other altcoins in the world coin index.