Re: "60 to 100 million of its citizens" is just straight up wrong. There was a Great Famine in China* - Mao did not murder up to 100 million citizens. Are you serious? Your own source says as much.
Re: Social Credit System (SCS) - By pretty much every metric the SCS has not resulted in massive discrimination on the scale of racism and sexism in the United States. However this may change. But for now this is not really relevant in terms of making a comparison.
Funny enough I don't really like China that much (or any large country) for a variety of reasons, but your reasoning is both absurd and factually incorrect. It's literally propaganda. Please educate yourself before making outlandish claims. China murdered 60 to 100 million of its citizens? Jeez - the American education system is an embarrassment.
* Though the famine should not and cannot be compared to murder, anyone who has read the literature probably knows that Mao's overzealous policies during the period probably increased the death toll, but even so that cannot be said to be "murder". Saying such is propaganda and more importantly, wrong.
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Also, to say American passed the Civil Rights Act without mentioning the Civil War is silly. The Civil War killed about 2% of the USA population. So if America was the size of China (which it wasn't), that would be like 12 million people dying, approximately half of the population generally accepted to have died during the 1960 in China (during the Great Famine).
I won't bother comparing Xinjiang to Guantanamo Bay...