Google is the steward of Chromium and Manifest v3 is just the beginning. When a single corporation has Total Control over what goes in to their codebase, we're going to see more and more abuses making it increasingly difficult to maintain healthy forks. Given the tipping point of users, certain websites now simply refuse to work with any browser but Chrome.
It’s just a renderer that calls home with hardcoded references to Google’s services. You can’t avoid Google if you use Chromium’s source code without patching it [1].
And unless you believe in ghosts putting the calls home back when you aren't looking, that isn't a problem for Brave [1].
[1]: https://brave.com/brave-tops-browser-first-run-network-traff...