If you are evaluating why someone would choose to read this specific title, it is important to understand that its appeal is very different from standard fantasy power-fantasies. Here is why readers are drawn to this type of content:
Total Control: Watching how a protagonist (or antagonist) imposes their will on others.
Systemic Power: Unlike slice-of-life stories, this explores the darker side of absolute power and the breakdown of human morality when rules and society are removed.
The Unfiltered: A raw exploration of human depravity and desire that would be censored in mainstream media.
Character Deconstruction: Seeing how "civilized" characters react when they are reduced to a state of slavery, which adds a layer of dark psychological drama to the erotica.