I find this thread interesting, but I believe many commenters are rationalizing why books are good by focusing too much on arguments around information quality, or trying to draw some differences between the motivations for paper vs digital writing, ... but I don't see it that clearly. I'm personally much more curious about others like:
- how much influence does it have the fact that you have to actually sit down, focus on something, sit somewhere comfortable, or not so comfortable but ready to work on a material... or the fact that it's a book, that it's long, probably dense to read, much more dense to write, that there's some sacrifice there, so you face the material in a completely different way you would face a random post or youtube video? we also definitely value very differently the things we pay for than those that are free. if you paid for it, you might want to rationalize it was worth it, and that might actually lead you to try to get something more from it that you would generally get if it was free and you didn't care. if you paid for it there's also a higher chance you were looking for it consciously, etc.
I think it would be interesting to measure those and others by collecting writing from different sources and presenting it on different formats. while I agree that on average the quality and the signal provided by a book is higher than that of a random video or blog post, I feel in many cases we are biased to give books too much credibility, and we really underestimate a lot of online content. there are many other factors, but I think we should open the perspective a bit more if we really want to discover why books are so good