I think Chromebooks have done so well because they're cheap and are purchased for locked down environments (education and people who really don't want complexity). Even then, I think they kind of demonstrate that the browser is NOT the OS because users and Google still felt the need to break out of the browser box, with both Android apps and Linux application support.
The browser is the OS that wraps the user not the machine. Just as Linux or Windows or Android wrap the machine and manage its resources, the browser should wrap the user and manage their resources (data, time/focus etc). In this regard nobody has succeeded. The browser isn’t finished until it achieves this
The browser is an application that renders webpages. It doesn't need any mystical vague purpose. Further, the OS doesn't wrap the machine, that's not even a good analogy. When you wrap something you've protected it or hidden it, or even ended it.
I don't need a browser to manage my time or focus. I need it to render websites efficiently so I can interact with them.
