WoW itself runs fine on Linux. Don’t expect any difference here.
That said, it used to be insane button bloat for everyone. Very complex rotations. Around Legion they started reworking it. Now most specs are reduced to rotations being 3-5 buttons. Work in the occasional cool down or defensive and things just fall over. This works out very well for the casual player. Controller support was added a few expansions ago. With the most recent expansion it’s reached good refinement. Some class/spec combos are easier than others.
An addon called Console Port makes it so easy to play with a controller. For leveling or daily quests, it’s perfectly acceptable. I’ve tried it and find it quite enjoyable. I particularly like it on my demon hunter. Though don’t expect to jump into competitive content. You need access to way more than a controller can provide. It slows you down.