The uncanny valley is strong. It's like adjusting the resonance of a filter--the closer you get, the deeper and more horrifying that chasm becomes. You just have to meet some real people who are totaly lying losers inside to they point they have abandoned their humanity, to see that even casting a real human body in the role does not eliminate the horror. If you slip up on even one tiny element of the humanity, it becomes a monster.
Oh god Rogue One. I know a guy who keeps describing it as a "good movie." Like, in those terms. Really.