When my problem with Chromium browsers is the fact that they're Chromium browsers it's fair to lump them in. The only complaint I have about Vivaldi other than "Google bad" (which is an unfair reductive statement) is that it isn't open source. But I don't care to try it.

The entire reason Chromium browsers are a problem is because it gives Google way too much power for controlling how the web works. They don't need to seek consensus any longer. They can just make it do whatever. I've even seen people consider it the reference implementation of HTML. It's sickening. Even if your "precious Vivaldi" and other Chromium browsers make tweaks to things it doesn't change the fact that Google was able to make that decision without caring how it works in other browsers because there really aren't other browsers now. Just fucking Chromium.

And for the record, it's extremely unfair to say that Firefox gets funding from Google while pretending Chromium browsers do not. Using foss products made by a company is very similar to getting money from them. Google has put an enormous amount of money into Chromium. Vivaldi uses that. It's like using public infrastructure then bragging that you don't accept money from the government. I genuinely don't care that Firefox gets money from Google because, despite the words you put in my mouth, my problem isn't "Google bad" (though I don't like them, but I don't refuse to use their products). My problem with Chromium is that it has too large of a share of browsers using it.