in your opinion which blockchain could beat the
Ethereum ... and why

?
I don't think there is another blockchain that can beat ethereum in our days now but maybe there are something may come but in the future .
so the thing here is that Ethereum will continue dominating the blockchain technology of altcoins ,
and this is the reason why Until now ETH is the dominance in altcoin world always second to Bitcoin the supreme currency .
I do agree that there are tons of projects that had the potential for it but they never really cared enough about their projects to make it become an eth killer. Look at the market right now, it is going down like crazy, any project that does something good right now would either go up, or at least not go down as much as the other ones and give some hope for the people.
This will be exponential growth when everything starts to go back up as well. If everything goes from 10 to 3, and you go 10 to 7, then when all goes back up 100%, they will still be 6 and not back to 10, while you will be 14 and break that price. This is what needed with these projects.