Excellent points.
I went to a very large high school. About 3000 students - split shifts. We did not have any “resource officers”. As far as I know, no one was ever shot or stabbed at school. No teachers were attacked. No students were attacked. There were the usual cliques but I don’t even remember any “bullying”. We were polite to our teachers and each other.
Something has definitely changed.
A couple of years ago I went to visit my daughters’ teacher at school with one of my daughters. The teacher told a student loitering in the hall that he needed to get to class. He cussed her out, using vile language. She did nothing because there was nothing she could do and the kids know it. Schools these days are more like asylums than places of learning.
If my kids were still in school, I would do everything possible to home-school them.
No guards, no metal detectors, no locked doors and virtually no violence. Certainly no direct disrespect for the teachers.
All this in the late 1960's when the revolution was just starting.