Also, I posted this in another thread, but I think it may be useful to the people in this one.
I found a few websites that provide interesting breakdowns regarding reader demographics and genre.
One of the most informative and reliably sourced is, https://cloviswhitman.com/2017/09/27/who-reads-in-the-u-s-and-what-do-they-read-the-sociodemographic-characteristics-of-u-s-readers/ However, this is obviously just regarding the U.S and may not apply well to other countries.
Another is, https://writerswrite.co.za/the-17-most-popular-genres-in-fiction-and-why-they-matter/ Also based in the U.S, it is an advice piece on genres, what they are, their categories/sub-categories, their advantages, and which are most popular.
Last is, https://mythsofthemirror.com/2016/07/11/reader-surveys-by-genre-and-gender/ While it's title would suggest it only breakdowns men vs. women, it is actually more useful. It breaks down books into 11 genres for both fictions and non fiction, then shows which are most popular. It then breaks down the novels by gender preference, which is insightful. Note: This is an opinion piece on a blog, but the statistics are sourced from https://www.statista.com/
Obviously, the data in each article doesn't perfectly match. However, it does paint a pretty good picture of the demographic breakdown of readers, as well as, some interesting facts about reading in today's world. Overall, I don't think anyone would view reading these articles as a waste of time.
One last thing, it does sadden me to see that so few men read across the board (Not to imply women reading more is a bad thing). As Charlie "T" Jones once said, "You will be the same person in five years as you are today except for the people you meet and the books you read."