Nobody has tried to systematically apply AI tutoring for adults. AI tutoring for children is easier because there are more people who understand the domains that need to be taught to children and can evaluate if the children have grasped the concepts appropriately.

It is clear that a personal human tutor can achieve incredible results, and almost everybody who has revolutionized any field you might think of is a product of such a system. Scaling that would be immensely valuable to society.