As I have been now regularly gigging for a decade or so again, I am curious as to your thoughts on this.
I play with a number of different people weekly (picture a non-preassigned rotating shift). Each time I go to a gig, I view it like a studio gig; you're not always familiar with how someone will approach a particular song. (Not to mention a portion of the time, they have never played with IEMs on a silent stage with a live audience).
Anyways, what do you see as the biggest miss is with others?
For me HANDS DOWN! Its dynamics. People largely don't seem to get it or the impact it has.
As I play guitar and bass, at times I play bass with another guitarist that I would view could shred me out of the room, but has ZERO grasp on dynamics. They don't get how to build a song, relax it, climax it, then land it.
Second would be timing/phrasing. Why are you soloing in 4/4 in a 6/8? (Clue phone did you know that's the reason your solo was too short or too long?)
What do you find is the biggest miss out encounter?
Actually, take that all down 1 level, the biggest miss is people who come unready/unpracticed to rehearsal. Rehearsal is for the SOLE purpose of bring together an orchestrating the final deliverable of what everyone has already practiced.
I guess I am more sensitive to this as the musicians I play with change weekly. If it was just 1 group, you could address it. Either they get better or they are discharged. Not the option in this situation. It's much more akin to coming together for a studio gig where you have the music beforehand.