Because if you spend enough time on the internet, especially the Western side, you start to hear voices of people who oppose their governments and not enough from those who support it.
Even many who are supportive tend to say that their government is authoritarian.
Generally the people I meet from such countries are here because they're liberals. So of course I'm going to hear liberal takes from them.
Sadly I do not know many nationals of these countries. My best friend in University had a Chinese girlfriend though. The relationship really didn't work out because she was so eager to return home, and he wanted to stay in the west. Sample size of 1, so pretty meaningless, but it's all I've got for empirical anecdotes.