Lol, 1 to 4 is just called "knowing how to drive". These cameras aren't a serious value add unless you're driving a massive tank, err car.
Parking in a dense European city is much easier with the rear camera. The pure radar version is ok but the camera really allows you to use every inch.
The rear window in trucks and SUVs is above the head height of a small child. w/o a backup camera there is literally no way to see if a small child is behind you.
So many parents ran over their own child that backup cameras are now mandatory in the US.
Backup cameras have been legally required on new vehicles for like a decade. It is well understood to prevent accidents.
There are hundreds of millions of drivers with new ones entering and old ones exiting the roads all the time.
If you want to practically improve safety you have to make the vehicles safer, you can't just hope pointing fingers at bad drivers is gonna do anything.