No, the issue isn’t the slopped distance, since the extra length is canceled by the reduced amount of force against gravity in the travel. Consider walking up a hill versus an overhead lift. Obviously we are considering a perfect ideal system, rather than inefficiencies of the human body. But it is wrong since the gravitational force is gm. g~9.8 mkg/s^2 or ~10 to make it easy. So the work is 100 Nm or 100 J. (N = mkg / s^2)