Most crypto go down with bitcoin and follow it's price movement but the fact that ethereum dominance is getting bigger this means that it is being more popular than any other coin but obviously it cannot compete with bitcoin and definitely can't overthrow bitcoin to become the king of crypto. Use cases of bitcoin are limited as compared to ethereum so in the future ethereum market share is going to be even more than the current one.
To compete I think it is possible, but to replace bitcoin there is no chance for ethereum, indeed ethereum is increasing until now, just look at the more users who transact with ethereum, even this coin is able to be in second position in crypto for such a long period of time , while many other coins have the same odds, that's why I say competing is very likely for ethereum.