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.

In which case I retract my last statement. Decades of experience say your technique rarely works, though.