Companies have gotten broken up before, like AT&T once did many years ago. In this case, a Google breakup would probably separate some of their services into different companies. At the very least Google (the “advertising” company) should be separate from Chrome (the “browser” company), because it creates a conflict of interest and creates monopolistic behavior.
In any case, trying to do something is better than doing nothing and hoping it turns out all right.
I think the poster is making a good point though- In this split, google the advertising company can freely contribute to the open source chromium. You need some model that leads the chromium maintainer to reject changes like this.
I’m sure there’s some mechanism in antitrust to prevent the broken up companies from doing things like that. Otherwise, a “primary” company would just contract out the old other pieces and they’re basically whole again.