To play devil's advocate: The US does also engages in censorship. Non-citizens are heavily restricted in the kind of political lobbying and contributions that they are allowed to make. We can argue about the distinction between political contributions/lobbying vs speech, but let's examine the intent behind the US laws: to limit the influence that foreign countries/organizations can have on domestic politics.
One could credibly argue that Chinese censorship of the internet falls along the same vein. A completely open internet would immediately result in China being inundated by western perspectives and arguments. An inundation that would be disproportionate, simply due to the west's economic lead and online headstart. One can understand any non-western-aligned nation being concerned about its domestic politics being strongly influenced by the western-free-speech-megaphone.
Overall, I still think that internet censorship does more harm than good, but it's worth considering the above.
One could credibly argue that Chinese censorship of the internet falls along the same vein. A completely open internet would immediately result in China being inundated by western perspectives and arguments. An inundation that would be disproportionate, simply due to the west's economic lead and online headstart. One can understand any non-western-aligned nation being concerned about its domestic politics being strongly influenced by the western-free-speech-megaphone.
Overall, I still think that internet censorship does more harm than good, but it's worth considering the above.