Western nations aren't exactly standing on a moral high ground, either.
It's also not applicable here since the grandparent already did a relative comparison of China with the supposedly better "western track record", so this comparison warrants a response.
The difference, in case you didn't notice, is that while racists are indeed racist and people against racism aren't, here the two sides are equally bad.
Practically I think moral high ground is an effective, if difficult to world, way to shut down whataboutism, but philosophically it is weak.
Countries like China don't tolerate that kind of internal dissent, let alone allow it to win sometimes.
However if you pick percentage of their population they imprison or civilian death toll in expansionist/imperialist conflicts? Or scope of global assassination programs?
But a point by point comparison is not really the point here is it? Obviously the American system is more capable of checks and balances than the Chinese system. That arguably makes the massive failures to use them worse. We disagree on what the word "trying" means regarding a state's actions I suppose. That seems fair, it's a fuzzy idea in this context.