And trying to reconcile that in some way is the crux of this thread.
Irrelevant to the topic at hand. It's not about what people are doing, but what or why they aren't, and the question about someone *not* taking a power is also a moot point, as the scenario posed is someone having a power and not using it.
Yes, that's the question. Why isn't it a plausible outcome that the player not using some ability presents a learning opportunity, though? Why is keeping any advice or insight about how using a power can result in a positive outcome verboten?
It's not impossible that is the case, but I do not believe it's as common as you present.
Maybe not in the immediate sense, but as a possible cause of a cascade effect, certainly. Someone gets mezzed, they can't fire off some helpful ability, which causes someone else to drop, which leads to the rest of the team getting overwhelmed. I've seen it happen before...
I mean, if you and your teammates are basically "soloing together", then maybe. For less optimized or maxed-out folks, it does matter.
As a general rule, sure, but since what resources each player has at their disposal can vary widely, a bit of a deep-dive into what particular powers could be best leveraged and how, when, or where, is worth examining.