You point to an important omission in my scientific article! My gut just assumed the reason would be 'drag', specifically reducing it. I guess the question is:

You point to an important omission in my scientific article! My gut just assumed the reason would be 'drag', specifically reducing it. I guess the question is: would it require less energy to push capsules/cars through the tube with an acoustic wave than it would to force them through the tunnel e.g. with some sort of propulsion?