When I was in college, we had office hours with the prof and the TAs, we had group study sessions, and private tutors. Or you could ask your friends. All of those required going somewhere at a specific place and time and asking someone else to give up their time for you.

AI gives you a way to get the same help without asking another human. Say of that what you will, but not everyone was comfortable asking other humans for help even back then.

Back when I was studying there were topics which I had a really hard time grasping. Having a personal tutor that I could ask specific questions and have a back and forth with would have helped a lot I think. At least the few times I did have such an opportunity that was definitely the case.