Problem is that when the libs started taking over education and other aspects of life, if the kid got in trouble at school, the parents started to come after the school and principals with lawyers. After many years of that, teachers are no longer allowed to discipline. We had strong discipline in our school in the 60s and 70s. There were no/few problems.
Freshmen year in HS we had a short, stocky, Italian guy lay gym teacher. Had everybody lined up across the gym floor giving us the what’s up in his class. One kid was acting up in very disruptive manner. Before that kid knew it he was flat on his butt. That was the beginning and end of any messing around in that class.