I feel like there's a missing step in the argument here. Yes Google's revenue comes from the web, yes Chromium being open source and paying for search deals are a hedge against anti trust, but why does it follow that they wouldn't want to dominate the browser space? They do, and it seems to be working quite well for them. But it feels more like a minimum effort hedge against antitrust then a demonstration of a healthy ecosystem.
Also, every time Chromium comes up you have people pointing to it like it's a counterpoint to their browser dominance. It's open source, so what's the issue? But the issue is that Chromium as a body decides whether commits make it into the browser and the decision making body is an invite only group of full time Google developers. So it is controlled by Google after all.