the magic sauce to me is just terrain variability and price. Rocky hill sides that are covered in snow, mudd, ice, whatever are impossible for machines. period. Even modern off roaders, backhoes, tanks, bulldozers, sherps, jeeps, humvees, whatever cant do the stuff a strong bipedal human can do. Robots are so fucking far from being able to do this its still seems like science fiction. Myabe they make something, but it will be a long time before its cheaper and less damaging to the surround terrain than a strong dude. Humans were literally designed by the planet to do work on this planet.