I would say the complexity comes by means of how fast you need to make decisions based on procs. Some jobs have very predictable rotations - or their procs may simply be a matter of "when it comes up, use it immediately and move on." For Dancer, it is very much a prioritization system that changes every, single second based on a dozen different internal and external variables. This isn't unique to Dancer, but it very much is the heart and soul of Dancer.

One of the greatest things about dancer is that its combo chain can only be broken by either dying, teleporting, or letting the timers run out for that proc - and they tend to be pretty long timers. This means you have incredible flexibility to deal with situations in the way you see fit, and you're not punished for temporarily stopping your combo to do something else. You can start a combo chain, pause it to do something else real quick, and then pick up where you left off. This means optimization is monstrous because the options are near endless. I think this will mostly fix itself as a player spends more and more time with Dancer. However, it can be a bit overwhelming at first.