Let's not confuse ourselves here. The opposite of one evil is not necessarily a good. Police reviewing their own footage, investigating themselves: bad. Unreliable AI beholden to corporate interests and shareholders: also bad.
Ya 'all like surveillance so much, let's put all government employees under a camera all the time. Of all the places I find cameras offensive, that one not so much.
Cameras in a teacher's lounge would be ridiculous but, in principle, cameras in classrooms make a lot of sense. Teachers are public officials who exercise power over others, and as such they need to be accountable for their actions. Cameras only seem mean because teachers are treated so badly in other ways.
Sure thing, buddy. They exert such power that they can barely make teens stay put for dice minutes without fucking around with their phones. So much power.