Actually, you can make the comparison. In the contemporary period, the US has implemented a torture regime worldwide, regularly executes innocent people (as the Innocence Project established), has deeply rooted systemic discrimination, has many states taking away women's rights and targeting trans and gay people -the list goes on and on. China does some of these things too, but the most extreme example of HR abuse in China -its campaign against the Uyghurs - does not involve the deaths of many people, though its campaign of cultural indoctrination still constitutes a crime against humanity. When you take into account other countries that commit major human rights abuses with US support, the list goes through the roof. What Israel does the Palestinians is easily comparable to what China does to the Uyghurs (with a lot more Palestinians actually being killed) and would not be possible without US support.
When you go into history, the situation gets even more complicated. The US is literally built on genocide and slavery. China is not, though the Chinese civil war in the 1800s killed 20 million people, the Chinese famine of the 1950s (caused by bureaucratic incompetence) killed about 25 million, and the Cultural Revolution -the one example of real government malevolence =killed about 500,000 people, though the numbers may be far higher). So, yes, the two countries are easily comparable, though in many ways the US is worse (historically, at least).
The OP raises some really interesting questions. I suspect you could get some really good stories as the members of the Chinese JL wrestle with these issues. But, as others have pointed out, it would be good to see American superheroes do the same. Especially given the reality that the US is not really a democracy. It is a plutocratic state and the voter suppression laws being brought in in many states will soon make any democratic credentials that the US has risible.
A final point to consider is that Americans need to learn to understand that their (mythical) experience is not a good model for the rest of the world. Whatever else you can say about the Chinese government, it is responsible for lifting about 800 million people out of poverty in an incredibly short period of time. When surveys are done of trust in government, about 85% of Chinese trust their govt, based on its real accomplishments and based on the fact that many of them remember when their prospects in life were much less than they are now. By comparison, about 30% of Americans trust their govt - based, again, on the idea that the govt is either not doing anything for them or is so corrupt that it is controlled by wealthy interests. The latter point is largely true, so you can't blame people for their perceptions and feelings that the system is rigged. By comparison, a lot of Chinese can legitimately feel that their govt's number one priority is making life better for them and they would be right.