There are so many choices about how to proceed with initiation, which targets to take down in what order, which methods to use to delay or hasten outcomes.
Or... it's about going 1,2,3,4 and 1,2,3,4 and 1,2,3,4 on the quick keys again and again until everybody is dead or you need to start running around waiting for your abilities to cooldown. Maybe sneak in a shot from your gun once in a while if you're too lazy to move your hand to the quick keys.
I exaggerate of course, since that's not always the case but that's ALL cooldowns do. As Alex said, cooldowns do more bad than good. It's not the cooldowns that give you the choices, the only thing they do is force you into patterns and circles and it's very evident especially when you have to deal with enemies that are way below your power level.
These choices can exist without the cooldowns and the whole thing would be much better without them.
Also fuck off with the "challenge". You and all the cooldown lovers who can't imagine gaming without them, you keep asking but you never actually listen.