I used KDE for years only recently switched to Niri, what I can say for KDE is I don't have to dicking around config files and nice features that are missing from other WM/DE like ICC profiles and HDR also very easy to customize. The reason I switch is because KDE getting too good and boring and using Niri reminded me when I use Linux for the first time again (same with switching from Windows to Linux because Windows is boring and barely customizable and cuntpilot)