Controller Support on PC

I really haven't played POE2 since launch, but today I logged in and figured I would play the Druid. One thing that really sticks out to me as something that I thought would be better was controller support on pc. The controller support isn't terrible on it's own, but why does the mouse and keyboard functions cease to work at all while in controller mode??? Some tasks like managing the passive tree, and working in the stash and inventory would be considerably easier if they were still functional. I can't understand why they seem to be disabled in controller mode.

I play other ARPGs that have a completely SEAMLESS transition from controller to m&k. Why is it so cumbersome in POE2????