I could get behind this idea if it could be implemented to only occur from drops that would inflict damage on the jumper, and only negates some fall damage, not all.
That way people can't abuse on stairs or a hill, and aren't going to try goomba stomping someone from miles up just to brush it off no problem. A 50% fall damage reduction seems fair.
(Although tbh if I landed on someone from a big fall I feel like I would get more hurt by their presumably not obese body, lol)