I mean, it's body horror, yes, but there are a lot of steps between "suck fat out of a corpse" and "inject it into a living person" that somewhat mitigate it.

If it would save my life, I would do that, but I also agree that doing that as elective surgery sounds like literal insanity to me.

If the choice is between injecting corpse fat and eating 3 cheeseburgers a day for 6 weeks, I'll have the cheeseburgers, please.