Some authors seem to chop up their novels into 3 or more novellas. Vandermeer's Southern Reach was all released around the same time and could have been one boo

Some authors seem to chop up their novels into 3 or more novellas. Vandermeer's Southern Reach was all released around the same time and could have been one book from the outset. He would probably deny it, but w/e. Can't say I blame authors. Word is that people on average don't read more or less than in the past. If that's true I wonder what's responsible for disparity. Are there more authors than before?