Tutoring
I recently saw David Perell explain Benjamin Bloom's concept of combining Mastery Learning with 1-on-1 tutoring.
Mastery learning is organizing learning into a series of concepts. Students need to master a lesson before learning the next lesson, which builds upon the previous lesson. 1-on-1 tutoring is conducive to mastery learning because students learn at different paces.
There's a massive oversupply in PhDs and a massive problem in education. Combining this allocation problem with Bloom's idea, there's a natural fit. PhD students and postdocs can tutor (on the side or fulltime). If there is a standardized curriculum, you could even have an Uber type service where you find a tutor for a specific module - you wouldn't need an exclusive tutor for a specific subject.