With examples in the past of games with a rich and enjoyable pvp/pve with just 8 buttons (GW), I think being able to reduce our skills hotbar to something like 16 buttons may be nice. Not easy to do, sure, but a nice thing to have.

IMHO the difference and variations we can get on a single job does not rely on 123,456 different skills to cast, but in the multiple interactions between few of them. Look at BnS, there combos depends not only on what you cast, but also on what the foe replied with, and if the skill landed or not. That surely adds much deep gameplay than have to choose between tons of different skills, the latter ending, as you all know very well, to just the use of only the "right" skillset and anything other may also not exists.