I think his point is that, even if you think it’s ugly, the nature of a web browser makes it irrelevant. The web browser is a window, 99.9% of the surface area goes to the website. Which is good. We could have prettier browsers which showed off more chrome, but that would be bad because we want to see the website.

Also, the UX of most browsers is basically the same. Browser UI has converged on one layout that works, and Firefox has it. It’s really indistinguishable from chrome.