Polkadot and Avalanche has a better chance to become a better version of ethereum but there is one thing that is very clear here, ethereum is oldy and these two projects are new comers, it's juts like saying bitcoin is oldy but we have better bitcoin wannabes, isn't it? So why haven't any defected bitcoin still? No matter what new projects brings or Introduced old projects will still always be on top
That is just the fact, ethereum is old and people like th embrwce such more but not in all cases, litecoin, EOS and many were old and yet overtaken by polkadot, so it depends. But I just see about ethereum is the DeFi and that people tend to investore in it. This will make it more even difficult to be overtaken by any other coin. Also, the gap between ethereum and the second strongest altcoin is very far and clear, this making their chances for such possibility of any other altcoin overtaken ethereum to reduce.
indeed, if we look at the gap from marketcap between ethereum and the others altcoins is so far,
thats why its impossible for other altcoins to overtake ethereum,
but if we talk about a chance i think BSC, cardano and polkadot is the best altcoins to compete with ethereum