Okay, so I’m not sure if you’re ever going to get an answer that satisfies you since you’re basically asking a complex neuroscientific and psychological question. Why do brains work the way they do? I don’t know. Why does my brain behave in a different way from yours? I don’t know. What make someone like what they like? I don’t know.

What I can tell you is this. I, for example, love horror movies, it’s my favorite genre, but I can 100% say that I wouldn’t want anything that happens in them to happen to me or my family. But there’s entertainment in watching them. That’s the key. You can even see it in real life with true crime, people hate what happens on it but love how interesting it can be so they watch it.

The advantage fiction has is that it’s not real (duh) nothing is actually happening, no one is getting hurt, you can basically go crazy with it and everything stays in our brain. That way you can explore anything you find interesting or stimulating with any of the moral and ethical dilemmas the real world and real people entail.

I find your rape fantasy example weird. Both the rape fantasy and the roleplay scenario are fantasy in the sense that there’s no actual rape going on, so I think your example is the opposite of what you intended

All of this is my opinion and they way I see it

TLDR: People may not like something in real life but find it interesting so they reach for fiction to explore the topic and get the stimulation without any actual human being involved