I use and prefer GNOME on my work machine, but I use and prefer KDE Plasma on my more consumption-oriented gaming desktop and light laptop (used basically just for web browsing):

• Plasma is noticeably lighter on resources than GNOME Shell, which on my laptop makes the difference between its fans running at idle or not.
• Plasma is generally far quicker to adopt gaming-oriented features like VRR, tearing in Wayland applications, and so forth.

My resulting desktop is effectively identical on GNOME Shell and KDE Plasma: a persistent top bar across all monitors that contains a clock, media controls, and system tray, and an autohiding dock with my running applications and launcher. Stability-wise I’ve found Plasma to be slightly better in this aspect, as the GNOME Shell setup requires the use of the Dash to Dock and Dash to Panel extensions which sometimes behave unpredictably or cause the Shell to restart, while my Plasma setup can utilize just the vanilla Plasma Panel with no need for any additional applications (such as Latte Dock, which I’ve found to be similarly unstable these days as the Shell extensions).

In all fairness I like both, but I have a pretty clear vision of how my desktop should look:

• I want icons to press to start my most used programs.
• I want these icons on the left of my screen, so they don’t take away height with is scarcer than width on any 16:9 screen
• I want a small top bar that gives me a systray and the time+date(yes, I forget if it’s not visible all the time)
• Nothing on the desktop, it’s for showing pretty nature pics only

Both GNOME and Plasma do a good job at that(gnome needs extensions) and I prefer GNOME‘s minimalism and app starter over plasma‘s start menu.

But I also have some workflow related things GNOME just can’t do. For example I like my browser to always start on the right half of the screen, maximised height but half the width of the screen. My console should start on the upper left quadrant of the screen and the lower left is reserved for either another console or the first one maximised to the left half.

Basically the DE has to conform to my OCD and plasma is great at that. I can setup programs to force certain sizes, positions and ignore geometry requested by the app itself. I can still adjust it freely, but I set default parameters so to speak.

So I use plasma. Also I think relying on a dozen or so extensions for my workflow in gnome is too fragile.

My two main reasons that I prefer KDE of GNOME are:

• I grew up with Windows so I’m used to its layout and with KDE I can achieve something very similar rather easily.
• VRR on Wayland is built into KDE, and works as expected.

I mainly use my PC for gaming and for me VRR is a must, so it’s nice that it’s built into KDE Wayland already.