This is still the case. KDE is full of bugs, bluetooth does not work properly (it fails to swap between hidef to a microphone/speaker setup automatically), 4K monitors have all kinds of problems (though KDE 6 fixes quite a few), hardware decoding in firefox/chromium for videos is a horror, the stupid fan starts all the time out of nowhere (by far the most annoying intel machine behaviour, thermals in windows are much better), and battery is dead after a three-four hours max (and usually much worse than windows on the same horrible x86 hardware).

A macbook air is miles ahead, unless you confine yourself to old hardware. I moved from thinkpads + arch to mac + brew. The experience is insanely better.