I think a good place to start is “anyone in the world who wants to learn and is hindered by their school and teachers”. Not “this must work in every American school from the start”.

A smart kid with a phone in Kenya should be able to have a shot. Wikipedia allows this. Khan Academy helps. This in the extreme is Khan Academy but potentially for every course a kid (or adult) could want, generated on demand from scratch if need be.

The next optimal study session generated for your current state of knowledge, energy level, learning goals, by the teaching agent who is provably the best at delivering that lesson for you, using the optimal mediums for your context. Video at home or in a class, audio when on a bus, printouts if you want. Add in spaced repetition and a few fun quizzes, gamify it. Let each person fulfil their potential unhindered by the resources of their school, parents or country.