For some long time, the Ethereum and Cardano was for me like Ripple and Stellar. Their CEO's have kind the same history, both were employed in the first company and left it for some reason to create own project. In our case better to keep all of these coins, because one of this coin will hit the highs and second will go up after it also.
everything is very simple. they created their coins because they wanted to make more money, but I dont think they did it because of the technology, that's why I believe in ETH more than in ADA.