You didn't even get to the covid restrictions, and parents calling teachers anti-American and traitors and Nazis for supporting mask and vaccine mandates. Teachers were getting death threats after being told they were "essential workers" for a year. Meanwhile they have to use their own funds to buy their own body armor, because they have to buy that along with pencils and paper now.
Teachers are not always 100% sympathetic. When courts in Illinois shot down school mask mandates, teachers at a high school near me retaliated by sequestering unmasked students in a room and not teaching them.