There is a Wall Street Journal article on the benefits of "slow reading." It emphasizes all kinds of benefits of this practice: "really, really enjoy," improves "ability to concentrate, reduces stress levels and deepens their ability to think, listen and empathize," offsetting "the ever-faster pace of life, such as cooking the "slow-food" way or knitting by hand," "slowed rates of memory loss in participants' later years," improving the understanding of "others' mental states and beliefs, a crucial skill in building relationships," and "a return to a continuous, linear pattern, in a quiet environment free of distractions. Advocates recommend setting aside at least 30 to 45 minutes in a comfortable chair far from cellphones and computers. Some suggest scheduling time like an exercise session." The words "learning" or "knowledge" do not occur in the article.
I doubt that the advantages mentioned are the primary benefits of reading. In fact, I dam sure that reading builds "crucial skills in building relationships." I think it atrophies that ability (which is not necessarily a bad thing).
There is also the claim that "many recommend taking occasional notes to deepen engagement with the text," not for the sake of extracting knowledge, of course, but to make reading more, like, say: cooking or knitting. I ask myself, if this "analysis" is true, why not cut out reading altogether and go for cooking and knitting right away. But I am unfair—the "or is not an exclusive or that is meant to exclude any of these activities, but rather an inclusive one that enjoins us to do all of them, as long as we don't try to do them all at the same time, as that would not be "linear" and "continuous" enough, leading to an "ever-faster pace of life."