Its mostly the devs and the bad decisions they make around GNOME, for me i use a lot of apps that require Server Side Window Decorations (SSD) to be useful, specifically apps like Foot terminal (default gnome console or gnome terminal is not featureful enough and neither have sixel support, whereas foot terminal does have sixel) and gnome doesnt have any SSD on wayland, and GNOME also lacks customization features and doesnt have a standardized theming API and the GNOME devs consider themes to be “unsupported”. Unlike on KDE Plasma where themes have a standardized API through the toolkit (qt) and are officiall supported. Also GNOME in general lacks basic features that require extensions whereas on other desktops you have things like a systray as a default.
running in the background isnt a system tray. every other desktop on the face of the earth has a system tray. It’s a basic espected feature and i use system tray functionality all the time.