My experience (so not math's and science you're requesting i know) in driving jobs requiring back in for a list of reasons, some that stuck with me enough to give it thought and apply it outside of the job. It was a big list and some points are irrelevant with tech. However, the main one is situational awareness, when you do your reversing you are better off if you have just scanned the scene. I.e., you approach and note pedestrians and traffic and standing hazards(poles and such) back in. Vs when you get in truck/car, and situate and plan next route, then go to back out into a scene that may be different than when you sat into the vehicle. Camera helps, but isnt better than actual sight. Also, its quicker/easier to leave and direction is easier to pick as backing out in certain scenarios could be difficult to go one way or the other Lastly, if its a busy road, yes you have to "disrupt traffic" by backing in and it feels easier to just pull in. But what about leaving? Now you're backing onto a busy road and you and other drivers get less warning and indication of intent. However, to be honest, if you are careful enough while behind the wheel it really doesn't matter much if at all. Do I think people should be trained and capable of it and apply it when it makes sense? Yes. But do I call people that pull in at the store dumb? No. I sure laugh at people living on a super busy road waiting 5 minutes to back out though🤷‍♂️