For me, its the concept. Both from the perspective of the predator and the prey, that a living thinking being is going to be food. Sustenance. Maybe a tasty treat. Especially in a consensual or semi consensual scenario.

The conflict between preserving another person - maybe a loved one's life and very existence - versus having them as a meal. Satisfying primal urges of being sated and having something tasty, or maybe some sexual pleasure for just a single time.

Or from the prey's perspective, to be willing (or unwilling but having no choice) to give up one's life for the fulfillment of another's very most basic needs and desires.

I don't enjoy the killing or the pain or the bloody gore that much (Although they can be kinky fetishes on their own, they are not what makes me love vore)

Even as far as domination is concerned, I most like when the prey has given up fighting and accepted its fate - as food.

An especially sexy part is taking the consensuality to the extreme. When the prey is more or less force feeding themselves to the predator that is either unwilling, or unable (due to injury, weakness, exhaustion or moral objections) to eat them.

"Oh you poor thing, you look starved. Here, have me, I will give you some strength."