There is no meaningful technical criticism of Chromium that I have seen. All of the anti-engine folks’ main argument seems to be “it has the Google stink on it”, but I can’t see how that is relevant in an application explicitly designed to avoid their ad/tracking/cloud services. It’s just a renderer.
What it is, is a backsliding into the days of IE where only one implementation was correct. Competition, yes, even at the engine level, is critical to a healthy web.
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].