What you said was very shallow and limited. You’re not entirely wrong though, but I can assure you there’s a vast number of NTR enthusiasts who don’t fit into any of the categories you mentioned.
Take me, for example. I’m a woman, and the reason I enjoy NTR is because I find it incredibly sexy when a woman abandons her perfect boyfriend for a womanizer, masculine, muscular man who simply pleases her far better. She has the perfect boyfriend—flawless and ideal for a lifetime—but the sheer intensity of physical attraction and overwhelming sexual pleasure she feels for the other man drives her to give it all up for him. And when she does it while humiliating or emasculating her perfect boyfriend, it’s even sexier. For me, everything about NTR revolves around the idea of "superior" masculinity, if a NTR doesn't portrait this, it's garbage. (shotas being portraited as bulls are one of the most disgusting things in any hentai genre)
As you can see, it has nothing to do with empathy for the stronger or weaker party or any of the other reasons you brought up. To clarify even further, this is purely about fiction for me. Just because I enjoy the dynamic of masculine, muscular men dominating women and conquering them from weaker, effeminate men in stories doesn’t mean I’m attracted to masculine men in real life. In fact, I’m not particularly fond of them outside of fiction. But in this context, the dynamic is incredibly arousing to me. It’s no different from how some men enjoy yaoi without feeling any attraction to other men in real life.