That’s an interesting take. I agree, most male serial killers seem to kill out of rage/sexual entitlement, thinking of all women as a single “thing” that they take out their revenge on for their perceived rejection (basically, they are/were incels).
However, men still actually do have power over women, whether they think they do or not. Many male serial killers start out assaulting women in other ways (rape, groping, domestic violence, etc.) and are either never prosecuted or are given slaps on the wrist. This is definitely a power imbalance. Plus, of course, the very physical power imbalance between a larger, more muscular man and a smaller woman.
But you’re probably right about the thought process, for the most part.