I have two. The Ritual and Drowning.
The Ritual is pure smut. 61 chapters and every one contains a graphic, demeaning sex scene. I’m convinced the author was an adult film screenwriter and decided to try their hand at writing a novel. There isn’t a single likable character in this book.
Drowning isn’t a great work of literature. I felt that the characters were very two-dimensional. I hated how naive the author made the protagonist. It made me have a lack of sympathy for her. The ending was series finale of Dexter bad.
“His Pain” by Wrath James White. I was trying to give Extreme Horror / Splatterpunk a chance because a booktuber I like reads a lot of that. I had my prejudices but decided to at least pick 3 books by different authors that fit the genre, and try to go in with an open mind.
“His Pain” was extreme all right. Extremely excruciating to get through. I don’t think I’ve ever encountered a published author (with loads of high reviews and everything) with such pathetically bad writing. Then there were lazy tropes, handwaving, medically and anatomically impossible ideas - it was everything I was afraid Extreme Horror would turn out to be.
One of the other two books was actually pretty enjoyable though, so I know the entire genre isn’t like that.