As an American, I can freely oppose the current regime. I routinely say, both online and in real life under my government name, that Donald Trump and his cronies are criminals, that everyone should work hard to stop them from achieving their goals and ideally they should all get life sentences once we throw them out of office. I’ll never face legal or even professional consequences for saying this, and even within the most authoritarian regime in generations few officials argue that I should.
Unless I’ve been severely misinformed, someone saying similar things about Xi Jinping on a Chinese tech forum would be swiftly banned and likely arrested.