Well again that's great for you that all the apps you use worked, but a lot of the KDE apps I use are broken with some themes :) I'm sure they would work fine i

Well again that's great for you that all the apps you use worked, but a lot of the KDE apps I use are broken with some themes :) I'm sure they would work fine in i3wm if you used Breeze but I have had very mixed results on any window manager with qt5ct, some apps play nice with it and some don't. It's not just the system settings that are broken for me, I just picked that as an example. Sometimes it's useful outside of KDE because it's the best way to configure global settings for some KDE apps, not just the shell and window manager. I've looked into it and it has nothing to do with optional dependencies, there are actually just issues with some themes and some apps. But generally I think it's a bad idea to try to run any KDE apps outside KDE, or any GNOME apps outside GNOME, etc, those apps work much better when used with their respective desktops.