I'll be really happy if UWP will die. I don't care for the visual side it offers at all, and the UX is simply terrible compared to the good old Win32.

Maybe I'm missing something, but the feeling I got regarding UWP is that it is an effort to unify the UX across all platforms and devices by aiming to lowest common denominator of all platforms. It meant that simple and useful utility like calc became a visually bloated app with sluggish UX. It meant every app takes double the screen size and offers half the functionality. In short, it made useful computer programs into passable mobile apps.

Isn't it obvious that mobile apps UI/UX is poor and is only acceptable as a compromise due to form factor limitations?

Did the strategy folks at Microsoft thought sacrificing the desktop will get them the mobile?

It meant that simple and useful utility like calc became a visually bloated app with sluggish UX.

That's an excellent example. A calculator does not need a loading screen, nor should it take over a second to start on any remotely modern machine. Fortunately MS have released the source, so you can see for yourself just how much bloat there is:

https://github.com/Microsoft/calculator

To compare, you can also see the source of the old "classic" calculator from Windows 2000 here:

https://github.com/pustladi/Windows-2000/tree/661d000d50637e...

That said, Windows CE was an attempt "to unify the UX", being basically a subset of Win32, and that didn't cause anywhere near the same level of disgust, so I'd attribute the bloat more to the cruft of "modern practices" than anything else.