Yeah, I adapted them from my JS Anki deck. Also ended up cutting out a lot of stuff out that turned out being less important than I'd thought as a new learner of JS. I'm hoping the courses are more useful than those a learner would create themselves since as a proficient JS user I have a better idea of what skills are actually needed.

Similar to your thoughts, I'd love for this or something similar to eventually replace textbooks. It'd be great to have experts in every field build interactive mastery courses that help you both learn quickly and retain the knowledge long term.