soix - something the speakers are actively doing, vs effortless performance - good point, I agree. When my system sounds good, I don't think it is "doing" a lot, I just get into the music. Trouble is, there is a huge middle zone. Music is quite good but something is not right. Like a too insistent tweeter. But then I find out that the problem is clear with some music, not all.
Very often I have suspected problems in my system, only to find that I (mainly) hear the same problem in my system nr 2, and from digital as well as analog, and so on. It is (mainly) in the recording. Can better speakers help with that? Or - should they? What about the raw truth? I think we are often chasing problems in our systems that are in fact problems of the recording and production of the music. Although I do agree that speakers can exaggerate recording problems, like sibilance, too hot takes, etc.
In my experience, there is one problem that dominates. The music sounds fine as long as it is fairly subdued, sparse, not too many instruments, etc. Often the verse is fine, but then comes the refrain and chorus. The whole band rocks on. Not to speak of the band AND a full orchestra! What happens? Distortion! My impulse is to turn the volume down. And then, up again, at the next quiet passage. I have not yet found a speaker that "cures" this impulse. Although some hide the distortion better than others.