You see these kind of dynamics with a number of things.

Years ago, Philip Greenspun wrote a post noting that there was no real middle ground between a magazine article and a book. (This was in the context of the web maybe addressing this--though it mostly hasn't, longreads and things like that aside).

Something either fits into low single-digit thousands words length or it needs to be a 250+ page book. In some ways, shorted attention spans make this sort of thing even worse. We still have books but, in my day job, we've mostly found that the 3,000 word white papers we used to crank out have largely been replaced by blogs and blog series.