To me, it is about power, but also about objectification.
If someone honestly believes that their feelings are all that matter, that your body is a toy for them, that getting their rocks off is more important than your consent… well, then they’re a rapist.
Look at how rapists talk before a trial, especially if they’re confident the “it was consensual” defence will work. They’ll often say stuff like, “I was just trying to get her to [come, squirt, [whatever]]”.
Like their sex partner is a tamagotchi or a video game.
So sure, it’s about power, but also dehumanisation.