I am not to familiar with the voltaire update of cardano and what new functionality it brings so it is hard for me to predict the effects of those upgrade but i can give my general view on the topic Cardano vs Ethereum. I still remember a few months ago, that Cardano pumped pretty heavily when they announced that the smart contract functionality is pretty close to being done. Since then though the price of Cardano has gone down pretty massively. That was again one good example for buy the rumor and sell the news.

For me tech-wise Ethereum will always be the project that enabled everything that we are having today, because they invented the smart contract functionality. All those other projects like Cardano, BSC, Solana just took that idea and tweaked it a bit.