Years ago, like right before khan academy became popular, I had started making a math education platform. The idea would have been to have many instructors and lessons/sections votes and scores that lead to the best courses that students could choose from based on any further preferences. It would have also provided a skill tree and automated assessments for placement and assessment. As new, better instructors got traction, they could have courses promoted. The financial incentives would be profit sharing between the platform and top educators. Never got it close enough to launching and then started a new gig and never got back to it.