KDE Plasma 5 + KDE Applications Matured Rather Well
Most KDE users are probably happy with the current state of the Plasma desktop and the state of the KDE applications. There's certainly less bugs in recent releases, KWin and the overall desktop is in better standing (though still improvements to be made such as showcased by the likes of KWin low-latency) with reliable Wayland support, and most would probably agree that the work out of this open-source project matured rather well in recent years with their focus on enhancing usability and other areas...