In a world where everybody uses Chromium, which is paid by surveillance capitalism.
I really don't know, but I could imagine a world where some people would pay for their browser (many would use the "community edition", probably), and where search engines would pay to be the default.
Google would probably still contribute to Chromium, they would just not directly have control over its governance. Maybe overall the web tech would move slower, but I don't think that would necessarily be bad.
In my world, people use whatever spying piece of crap browser a random app installed as a default for them. I really don't think anybody except a few enthusiasts would pay for a browser.
Written from Firefox.