Hybrid system, actually. No 100% pure system survived, ever. Be capitalist, communist, or technology philosophy bound. The GNU project tried to expand Unix with ITS editors (Emacs), utilities, ITS'like freedom and Lisp (Emacs and Scheme, again).

For a while the most used editor for Unixen wasn't vi or a vi descendant (vim), but Emacs, an editor alien to Unix. Knowing Vi was almost something 'mandatory' in order to manage servers' configuration under any Unix like OS, and ed on hard emergencies where even the terminal wasn't reliable enough.

Windows needs WSL2 and POSIX compat to be relevant today. Win32 itself doesn't run on top of a DOS like VM having almost a 95% of control of the machine, but on a VMS'like kernel with objects a la IBM.

MacOS itself it's just a Macintosh like UI made from NeXTStep scraps, a Mach kernel and pieces from a FreeBSD useland.