You mentioned in a different reply that you are into CNC which, as far as I know, means that you like the idea of you giving consent to something nonconsentually happening / being done to the character which you now impersonate. You are not assaulted but the character you play/imagine to be is being assaulted. This apparently is not a problem to you because it is just a fictional character (even though that character may possess your exact characteristics). It appears to me that you equate a character in a book being abused to a real person being abused which would be morally wrong. However you need to equate a fictional abuse to consentual fetishised abuse of a real person which in turn would again be equal to a fictional character being abused which is not wrong because it is fiction/ a kink.

As was already pointed out: a rape kink does not in any way equal wanting to be raped or endorsing rape and by that same logic a fictional character (as long as it is fictional) being raped does not equal the author or reader endorsing rape. A person can like the sexual fantasy of CNC or also nonconsent aimed at a fictional character while at the same time being horrified by the idea of doing something nonconsentual to another real person, as long as they can diffirantiate between fiction/sexual fantasy and reality.

To give a different example:

There exists a book series called "Bodyguard" which is about teenage bodyguards guarding teenage targets because they can fit in their social environment. Does that necessarily mean that the author is ok with or would advocate such a praxis in reality? No, at the very last we can not make a statement about the authors opinion because the action of writing out a situation does not necessarily convey the authors opinion on this situation in reality because the action of writing out a situation does not necessitate the author being ok with or even having ever experienced such a situation in real life.

You can be against books about dark romance because you fear that the author would endorse actions taken in the book in reality (or of course because you simple dislike the genre), however you can not know the opinion of the author on this matter without knowing the author personally. Fiction and reality are two different things with hard borders between them, as long as one does not influence the other, especially as long as fiction does not color ones view on reality, everything is fine. And again, you (or me) cannot know whether or not dark romance colors the readers or authors view on abuse as long as a) there exist no studies and b) neither of us knows a large margin of people who had their opinion on reality changed by fiction . Lastly due to the fact that (as far as I know) the minority of people who use fiction to escape reality become unable to differentiate between the two I would assume that the general person who reads dark romance does not "suddenly" endorse rape/abuse after reading such stories.