Computer posing problems to students, grading them, and walking them thru a solution works pretty well... for simple fairly rote tasks. If the goal is to develop initiative and original planning, then the student would be working in some unanticipated way, not one of the preprogrammed computer patterns. And the student's way might actually be less efficient, but nevertheless the exercise of devising a plan, and seeing what happens, and what goes wrong, is valuable. Indeed without any originality, progress will end. Having a computer grade that, seems impossible until AI progresses a good deal further. So I think optimal teaching requires a substantial fraction of human feedback, and I do not think massive online courses with everything done by computer, can provide optimal teaching. If AI reaches the level where it can do this, then the debate will become irrelevant in the sense that humans will be obsoleted. That being said, I don't see why textbooks have to be heavy, expensive, and made of paper. If things keep going, wikipedia will become better than most textbooks. Free too.