Xubuntu and XFCE on desktop RHEL-based on server Not really a fan here of edgy desktop environments, if anyone feels on the "It just works" philosophy, give Xubuntu a try. And of course, master the CLI.
Also why not give tiling windows managers a try ? You may check i3-wm or other wm if productivity matters and a steep learning curve doesn't scare you
While not very condusive to daily work (at least for me) you might get a kick out of CDE, the Common Desktop Enviornment that was created for the big iron days of Unix. It is in the Debian repros, and it is something different. Been playing with it on my testing partition (installed on top of antiX 19.2 base w/ runit init). The one downside I havent been able to get around yet is keeping track of open and minimized windows.
Nice video, Plasma is very customisable, don't know that I would bother with it though. I do like the look and feel of Windows but at the same time I am so glad to see the back of it for so many other reasons.