I am not defending Windows 10 and would never use it for personal use in its current state. That said, my understanding is that they skipped 9 because of all the existing code that looks at windows versions and could potentially match 9.x as "95, 98, 98se" as a matter of reducing risk. I do not have a current reference for this.

I would use Windows 10 if the default install was a stripped down version of LTSC and had zero telemetry. Give me a kernel, a window manager, sound drivers, video drivers, storage drivers, network drivers. That's it. Install size should be less than 500 MB and idle memory usage should be less than 512 MB of RAM, in my opinion. When I "view processes for all users" it should be less than 20. Aside from Windows Update and layer 2 discovery, there should be zero network packets initiated by the OS unless I specifically requested it. Call this one LTSZ for Zero Cruft.