People who use Debian for desktop, why?

It's not server-oriented. There are people who have used it as a desktop for 25 years.

Debian is the upstream for almost everything now. IMO, the more layers are added to Debian, the more delays or errors that can be introduced. For example, Mint was famously withholding security updates a few years ago. Ubuntu has snaps which have been consistently problematic ... enough that I switched to Debian on three systems because routine updates would routinely break Firefox.

Flatpaks have closed the gap. It is entirely possible to have up to date user applications on a stable, secure base system. Now that the Debian installer includes non-free firmware by default, the downstream distros are really just adding pretty wallpapers and color schemes. Not really worth it for the added overhead.

So I just cut out the middle man and go straight to the source.

Just my opinion, I've learned to appreciate Debian after 25 years of avoiding it and using every other distro you can think of.

@zephyr "just" because it is rock-solid, even using testing+Sid packages!

My main use = games (steam, native ones, lutris/wine/proton), blender, multimedia...