Remember that the difference in drop down between bitcoin and ethereum wasn't that much as of 2017 so both started the bull together within a close range, meanwhile the 2020 bullrun case is quite different and on top of the delay in ethereum 2.0 which of course has effect on the price stability now.
..... ETH is practically useless. the only time you see it used is when someone wants to create a scam ICO token.
That's why ethereum is known as utility token that's, a center of different innovations in the crypto space thereby giving room and opportunity for scammers through ICO, DeFi and many more.