I think this is the wrong way around; Plan 9 prevented itself from becoming useful by changing everything so thoroughly that building an actual web browser was pretty much impossible. It was more or less guaranteed that APE (The "ANSI Posix Environment") would die from neglect. This neglect seemed intentional and people seemed happy to run plain white windows with black borders and congratulate themselves that their system neither had nor needed the massive shared libraries that Unixen of the time seemed to need.
The lesson seems to be, rather - don't build an operating system that can't build up enough infrastructure to run a browser. This is maybe less forbidding than, say, being forced to build an operating system that can support an entire Windows subsystem.
I have trouble understanding what it is that people want when they say they want "innovation" in operating systems. It seems like almost anything that was practical to do in the period when I worked with Plan 9 is now eminently practical and far more performant in user space; so why not go build it on top of a minimal Linux kernel and save yourself the trouble of building a gazillion drivers, boot loaders, etc.
The lesson seems to be, rather - don't build an operating system that can't build up enough infrastructure to run a browser. This is maybe less forbidding than, say, being forced to build an operating system that can support an entire Windows subsystem.
I have trouble understanding what it is that people want when they say they want "innovation" in operating systems. It seems like almost anything that was practical to do in the period when I worked with Plan 9 is now eminently practical and far more performant in user space; so why not go build it on top of a minimal Linux kernel and save yourself the trouble of building a gazillion drivers, boot loaders, etc.