I have a KDE desktop environment and it’s very attractive, and I haven’t had any glitches beyond issues with Flatpak (VLC being a recent one that I managed to fix).
…and how much GNOME / GTK are you pulling into that KDE because of app dependencies. I like Flatpak but it even makes this issue worse, from the theme mismatch (that can’t always be easily fixed) to effectively loading a LOT of GNOME components with those apps everything happens. I don’t see a point in using KDE if then you’re essentially running a LOT of apps that will depend on GNOME/GKT components.