Google has pretty firm control over the Chromium code base, so not much reason for them to degoogle it. Presumably the worst stuff is not publicized to avoid PR disasters, but just "Google does evil" is hardly a news story.
Vivaldi reasoning for not disabling this extension is that non techy user(s) would be suprised, if Google Meet didn't work the same way it did on Chrome.
They do offer a way to disable the extension.
OK, now tell us why this isn't an EU DMA violation – asking for a friend in Brussels
Because it's a new type of tracking that hasn't been explicitly banned yet. That's how these companies operate. They'll change something ever so slightly and go "you haven't told me not to use this yet! Nee ner nee ner nee ner!"
I sure miss the days when Google was a refreshing change from a Microsoft dominated tech world, back before they changed their motto of "don't be evil".
Fingerprinting, it allows Google to track exactly who you are across the web. Anything you look at or search for, Google can find out it's you basically.