Plasma has been pretty stable for the last several years I’ve been using it, especially X11. Wayland is buggier, but not terribly so, and it gets better all the time.

I’ve switched over to Wayland with Plasma now because it is stable enough for me now, I’m on Nobara.

I don’t really use Gnome, so I can’t speak to that experience.

If I were to vouch for a DE that is rock stable, it would be Cinnamon. I’ve never had any problems with Cinnamon. It’s not super pretty, and it’s a bit clunky, but if I want a DE that just works and gets out of my way, Cinnamon is my first choice.

It’s what I use for my business laptop, LMDE with Cinnamon, rock solid.

I should also add that I’ve always used fully AMD hardware, CPU and GPUs, and never brand new. Always a year or two old, so the Linux kernel has time to address bleeding edge bugs and such.