One problem I do have with Plasma (though this may just be how arch packages it) - Dolphin, the native plasma file manager, is not included by default. Yes, I know it's not much of an imposition to do pacman -Sy dolphin but a file manager seems like an integral part of the system to me worthy of being included in the base package for a desktop environment.
Little choices like that affect new user adoption.
Disclaimer: very happy user
Getting KDE Connect (Killer feature IMO) to work needed fiddling with the firewall, but while annoying at the time in retrospect it leaves a good impression.
Podman is availlable without jumping through hoops, and nearly everthing i need is availlable via opi (think AUR but mostly official, directly from OBS), if it is not in Tumbleweed allready.
In my experience, Plasma Desktop runs well even on old hardware and uses about the same amount of memory as Xfce.
And ask someone who isn't familiar with it to find a setting. It's a hot mess. Just a hot mess a majority of people are used to.
Yes Linux desktops have been a complicated topic. But it's incredible easy to build something less distractive than windows 10.
True, it's now significantly more complicated and there at least 300 more distros worth of fragmentation. But at least sound finally works!... usually...
Desktop Linux in 2021 is nothing like it was 20 years ago. Plasma Desktop is a great experience these days, and in my opinion, surpasses both the Windows and macOS desktop shell experiences while implementing features from both systems.