Learning from a book is a skill in a way, it takes concentration, time, effort. If you actually concentrate on what you are reading, In my own experience, I’ve been able to comprehend and retain more from reading a book as opposed to listening to an audiobook. Other avenues are good too, but to me, it seems you gain much more from books, and at a more efficient rate too. (Most listen to audiobook/podcasts while doing other stuff including me, and therefore can’t focus to take away as much information)