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OP, I think you're misreading this movie. Sid wasn't the villain, he was an obstacle. A perilous one that took a lot of work to get past, sure, but an obstacle nonetheless. He didn't have any way of knowing the toys were alive, and when he realized they were, he changed his ways.
The villain of the movie was the guy who tried get rid of a fellow toy who was clearly mentally confused just because he was jealous. He was ready and eager to throw Buzz to the wolves, up to and including leaving him to his fate with Sid- an act that he knew was basically a death sentence.
The movie is Woody's villain origin story, and the start of his redemption arc.