A lot of things have changed if we compare ETH in 2017 and 2019. Back then in 2017, we sought ETH as a replacement of BTC but right now it is struggling for its own existence as many of the alts have come up and are sought as to its substitution. However, the price of the coin had decline so much and looks way more far from the ATH that it achieved previously, I believe that it would soon rise and we will be seeing a new powerful ETH hopefully...
It seems as if it was yesterday, but you are right during 2017 there were many coins that were looking to replace bitcoin and of all of those coins ethereum seemed like the one that had the best chance to do it, in fact at some point it came incredibly close to having the same market cap as bitcoin since there was a difference of only a few billion dollars between each coin, the market of icos was incredibly strong and most of those coins were using the ethereum network so this created huge demand for ethereum.
And now only two years later things have changed radically, most investors have trust issues with icos, ieos are performing better but will likely follow the same path as icos, ethereum has not fulfilled its promise of becoming the new bitcoin and bitcoin reestablished its authority over this market and there is no one that thinks that it is going to be replaced soon.