They don't hate them, but it is an emberassment that a group from the same culture is so successful under a different political system that allows for more freedom. That combined with cultural revanchism about not breaking up the country (and having spent a lot of time there I can tell you it is strong) makes the existence of Taiwan as an independent nation a real sore point.

I don't think the CCP views Taiwan as more successful than mainland China. The CCP position is that Taiwan is already part of China and by that logic Taiwanese success is automatically Chinese success. I agree that cultural revanchism plays a major role.

They might not be more successful, but they are still very successful given the difficulties they face, and any Chinese person with half a brain can realize they give lie to the idea the CCP likes to propogate that there's something intrinsic to Chinese culture that requires an authoritarian approach.