Assuming "why does the Chinese government hate a free Taiwan?" is a real question, because Taiwan is where the survivors of the Chinese Nationalist government went after they lost the civil war with the Communists (and Communists and Nationalists kept kidnapping and murdering each other after that date), and because Chinese Communist Party ideology emphasizes unifying all Chinese.

See also the CCP's crackdown on democracy in Hong Kong. Hong Kong was another place where Chinese people lived with independent courts, a free press, and multiple parties and the CCP was not satisfied.