It's not just Mathematics, the discussion is about teaching vs learning. Ideally the recipe is: good mentor + good student + good teaching tools IMO for most

It's not just Mathematics, the discussion is about teaching vs learning. Ideally the recipe is: good mentor + good student + good teaching tools IMO for most disciplines, in the year 2022 CE, the critical point is student, not the mentor, not the tools. Internet resources can hack the mentor/tools stack, when WE are eager and hungry student WE will find a way.