The real proble with these cameras is that they provide a very narrow field of vision, and even possible improvements like putting wide angle fisheye lenses in them will only provide marginal improvements.
We had a rental car for two weeks with one. It’s very easy to become trusting of and addicted to the convienience of it to the exclusion of other options (physically turning your body around, using the rear views when backing), creating an even more dangerous situation because you’re paying attention to what is directly behind you and arent paying attention to things that might be approaching (rapidly) perpendicularly/from the side.
For predictable results, see the scene in Office Space where Tom, in a carbon monoxide haze, backs his car out onto the street and immediately gets t-boned by a pickup truck at speed. That almost happened to us, twice, when we had the camera equipped rental mentioned above.
Yeah, just because it has one doesn’t mean that you’re supposed to ignore your mirrors - but that’s what tends to happen. The main use-case is to check to see if there’s a kid immediately behind the vehicle, not to replace mirrors.