It's not an easy feature to test. A lot of magazines have used really fake looking inflatable or cardboard people. Radar systems are going to see those really well. Machine vision solutions may correctly classify the objects as non-human. You don't want your emergency breaks to go off every time a plastic bag floats in-front of your car.

Then you have far more complex real-world situations like this one. The emergency breaking works correctly. https://www.youtube.com/watch?v=X3rmevP6XVY

I'm not sure what statistics are available for pedestrian collisions. Probably nothing short of deaths are reported reliably at the national level.

To be honest, that is also a problem with human drivers

Hence, regulations requiring specific designs to lessen the effects of a human being run over by a car.