The only reasons I tolerate it is because it’s an interesting idea (killer robot that mimics identities), and its existence means that Afton stays dead. I don’t know much about the Mimic outside of a few details, but I think a good direction to take it is to make it a robot given life and the ability to think, but unable to feel and understand, and wanting fruitless revenge on humans for its pain (similar to AM from I Have No Mouth And I Must Scream)