I thought of one more thing. I have a 92 year old aunt who went to the Metropolitan Opera every week from 1939 to 1967. She told me that when the opera being performed was Italian or French, there was the usual noise in the audience. When the opera was German, you could hear a pin drop in the hall. The audience for German opera was infinitely more respectful than for other performances. So I think that much of it is cultural.
I don’t know if this is true in other states, but in Massachusetts, starting maybe 5 or 6 years ago, all performances start with an announcement about exits and emergencies, but also an announcement to turn off all cell phones and to not text or talk during the performance. It’s helped some. But for that reason, when someone does talk anyway, I go ballistic.