However, I'm not convinced that our OSs can't be much, much simpler. You can, almost reasonably, use DOS as a daily driver still. I have very fond memories of DOS because it was simple. Even as late as the early 2000s, if you wanted something like a MAME cabinet you'd often use DOS. You just plop some application and data folders onto a disk with like 4 system files and you were pretty much done.
Where is today's DOS? I suppose it's Linux, which is orders of magnitude more complicated (especially once you start talking about a GUI) and even Linus admits it has become quite bloated. I personally think we can do a lot better and I've been toying with the idea of putting something together because I'm just so sick of modern computing's bullshit.
PS: If anyone is aware of an organized effort towards this goal that already exists, please let me know.