I think the demand is there, just no one has the right combination of financial resources, technical ability to pull it off, the right sense of good design, and

I think the demand is there, just no one has the right combination of financial resources, technical ability to pull it off, the right sense of good design, and a way to make money off of it somehow other than by charging licensing fees (which is probably a non-starter if you want to grow the user base quickly and take advantage of network effects). The companies I can see who are in the right position to profit from developing and giving away an OS that's at least as user-friendly as MacOS or Windows and as open as Linux are Intel and AMD. But it's hard to imagine either of them making something that's a joy to use. Something Linux-based could work, but Linux is kind of stuck with a lot of decisions made thirty years ago. The kernel is pretty good, but the basic abstractions of POSIX-like operating systems are perhaps not what you'd design if you were creating them from scratch in 2020.