You are a little too understanding of the general population. What percentage of people will quietly apologize and change their behavior instead of becoming combative for being confronted for their assholery? In my anecdotal experience it’s probably like 75% of people in general become combative and you need staff to deal with them.
It's not too much to ask for people to act appropriately in certain situations. During a movie, or stage production, it is not too much to ask for people to shut up and stay off their damned phones. If you can't be relatively quiet for a few hours, maybe going to a theater is not for you.
The one time I can recall where I was annoyed enough with a fellow theater goer to engage them at all, it resulted in the obviously drunk wife berating me in the lobby for ruining her "date night" with her obviously embarrassed husband.
More generally, I have approximately a 0% success rate getting people to change their bothersome behavior. Loud neighbors are far more common and know they're being loud and don't give a shit in every single experience I've ever had.
I'm not afraid of confrontation, I just don't see the point when it literally never works in my experience.
