The thing is, a lecturer spends 20 minutes doodling this and can explain most of the same, especially if there is some ability to directly interact with the audience and clear up misconceptions. Maybe in the worst case a good lecturer takes twice as long to get the explanation across. If need-be, the lecturer can elaborate on any piece, or draw a completely new picture as the situation demands.<p>By contrast, making the fancy animated version takes 20 hours, plus another several hundred hours (or perhaps 1-2 orders of magnitude more) to build the framework underneath. Even better would be to make interactive explanations, but that would take dramatically more work than even the animated version.<p>If someone can spare the time to do it, it obviously has tremendous value, but each animator can only explain a tiny number of things in this medium, compared to, say writing a whole book with the same amount of effort. It’s similar to the contrast between telling hundreds of stories around the campfire or writing a novel vs. animating a few minutes of a Disney film.<p>Ideally we’d have ten thousand skilled animator&#x2F;programmer&#x2F;educators working on creating such explanations, sharing tools and ideas, coordinating effort to build more complete curricula, etc., but there’s not currently anyone paying them to do it, so today there are only a handful, working as volunteer hobbyists. There’s no incentive for current educators (say, college professors or high school teachers or textbook authors) to spend their time making this kind of thing, since it’s not an established and recognized genre yet, and a vanishingly small proportion of them have the requisite skills.