Ethereum has first mover advantage and is incorporating PoS.

That said the transition for Eth to PoS is very complex and there are going to be a lot of artifacts in the code that hamper it. It will be very interesting to see over the next 5 years how all these dynamics play out.

I'm personally invested in both. Over the next 5 years, I think eth is the safer 10x play and cardano is the riskier but potentially 100x play.

However, in 1-2 years cardano may not even be that risky anymore as they find their niche.

It may not even be such a war like bitcoin<-->iota. Perhaps ethereum and cardano co-exist happily.