There's a large difference between reading a book and reading social media posts or news articles: books require hours of concentration to consume, have long-spanning arcs of plot or other structure, and require significant use of our imagination (particularly fiction). You just don't get those three things from any other form of written media.

Signed in just to a agree with this. Over the years, I have seen many people bring up some trite form of online reading in an attempt to raise it to the level of what we typically think of when referring to book reading. It's a stance I really can't take seriously, both as a concept and due to personal experience. "The C Programming Language" did not give me vivid dreams or boost my writing skills, general creativity, and vocabulary when I first read it. A mid-level sci-fi book from the 80s, when I haven't done any for-fun reading in a while, does. There is clearly a cognitive difference between the very act of consuming each of these. In comparison, social media posts or news articles are far closer on the broad spectrum of reading to the the like of road signs and subscriber agreements. The mechanical act of reading is simply not equivalent over the broad range of content that can be read, and so its effects on the mind are also not equivalent. Related? Sure, but only by the fundamental understanding of symbols and language. Apologies for the rant.