I completely agree with you, because for me personally, if ETH is the leader of the cryptocurrency market, even though Bitcoin is at the very top. If you believe in ethereum and invest in this coin today, then when you reach the level of the beginning of 2018, ethereum will increase 4 times. This means that the amount of investment multiplied by 4.
Why would you or anyone ever say that ETH is the leader of the crypto market other than the fact that it is placed there at number 2 in market capitalization? If you take into account all the supply ever produced and the price, and you compare that with other similar smart contract platforms with similar ratio (adjust price and supply) then you realize they are basically all on the same level, except now ETH is not seeing as much DApp use as others.