> "In ~20 years they've had little success in replacing textbooks." I'd argue they have, just not in an official capacity. Even when I was in high school (earl

> "In ~20 years they've had little success in replacing textbooks." I'd argue they have, just not in an official capacity. Even when I was in high school (early 2000s) we relied on websites (and diagrams like above) more than we did our physical books, which were largely not useful for learning. The learners have embraced the power of multimedia and the web, I suppose the problem is that "I made website that makes it easier to learn" is not a photo-op moment like "look at us holding this iPad!".