Most importantly, it's away from most Windows userland, with cloud accounts, licenses, ads, and other unwanted stuff.

I don't see how that's relevant. The game studios can use whatever OS they want. It's not about "windows was never involved", it's about "I'm not subject to their BS"

Delusional about what?

The Windows API is just that: an API. An interface. Who cares whether it's implemented by Windows or Linux or whatever else?

Keep believing that, it did wonders for OS/2.

Make a point instead of pithy remarks.

No, this is not how this works. You have to actually explain yourself here so that others can address your point. Nobody wants to imagine arguments from a half-sentence.

IDK, the original Doom was largely created on a NeXT computer, with everything different from x86 and DOS.

It was an explosive hit of DOS-based PC gaming market nevertheless.

The tooling was created on NeXTSTEP, the game engine was on MS-DOS, using Watcom C/C++ and 4GW DOS extender, not UNIX running on MS-DOS.