"Although it's changing, books for me has largely been about someone taking the time to actually plan out, organize and go into detail on the topic."
I agree, except I don't think it's changing, because the end artifact of "plan out, organize and go into detail on the topic" I would still call a "book", regardless of how its delivered.
What I meant by changing is that online content has gone up in quality since the introduction of MOOC's and the realization that decent money can be made from training. What used to be semi-random collections of tips and tricks have turned into full blown courses.
I agree, except I don't think it's changing, because the end artifact of "plan out, organize and go into detail on the topic" I would still call a "book", regardless of how its delivered.