You are used to KDE and Gnome is very different But also KDE is buggy, I dont know how Steamdeck people make it better. If you chose Xfce, you will get a KDE similar desktop but more robust. Xfce can look modern with few efforts. MX Linux distro is a good example of a nice Xfce config.

Xfce allowed me to replace the default window manager by Bspwm. Also the panels are fully configurable. This is a totally different philosophy.

I use Xfce with Bspwm as a window manager. A plugin writes the window title in the status bar. Window decoration is just a rectangular outline. Its hard to get a more space efficient gui.