There's a crucial difference: the PRC just jailed 32 people for very-knowingly risking life sentences to voice their discontent around June 4 and (more broadly) the National Security Law that has openly erased Hong Kongers' right to free speech and free assembly.
If you're a Chinese citizen standing in the street next to Zhongnanhai to criticize the unelected ruler Xi Jinping, you are 100% going to be hauled off in an unmarked van and locked away indefinitely. By all means, mount some very justified critiques of the USA's treatment of BLM protestors, or its horrible track record around race relations, or policing, warmongering and overthrowing Latin American democracies- just be aware that 'the USA being bad' is not enough, when the goal is to justify authoritarianism (bordering on fascism) in China.