Some cars do have remote-control drive features these days, so you can reverse it from outside the car, but that's a super high-end feature (designed for getting in to and out of extremely tight city parking spaces) and relies on the chips that are in shortage, so that's not a solution.
We are but muggles, so I don't think we need to worry about teleporting children appearing in the time it takes you to get back in the car. You know your blind spot is clear and can see where your future blind spot is now.
Some cars do have remote-control drive features these days, so you can reverse it from outside the car, but that's a super high-end feature (designed for getting in to and out of extremely tight city parking spaces) and relies on the chips that are in shortage, so that's not a solution.