Well, it's also physics that there is a huge spot behind the rear of a vehicle that is blind to someone looking over shoulder from drivers seat. If a kid is there and hit, it's called a backover. In front...frontover. Kids are killed. These cams reduce that chance.
In front, blind spot can be up to ten ft out. A ten ft blind spot can hide several kids hiding in a game of hide and seek.
If I used my eyes, even if I get out before reversing, and look behind my car, then rush back into seat and go into reverse and look over shoulder, a kid could still run there. The cam can see them when I can't.
No one is going to like every technology. But some have clear advantages.
I have started bringing up the front cam before pulling out of garage, my garage is in a laneway and kids play there. I like to check that one hasn't scampered there before I pull out.