Check the top 1000 books on Amazon. Most of them have a shirtless guy on the cover, because they're smutty "romance novels" (read: porn for women) about a girl being swept off her feet by one (or more) billionaire alpha-males. There are literally tens of thousands of books out there about shirtless billionaire alpha-male vampires who can't wait to mate with you. Lucky you! And women eat that shit up! Men, not so much. Men prefer to watch actual porn.
Aspiring authors, get this through your head. Cover art serves one purpose, and one purpose only, to get potential customers interested long enough to pick up the book to read the back cover blurb. In the internet age that means the thumb nail image needs to be interesting enough to click on. That’s what covers are for.