The US version is a system that calculates the risk of loaning money vs being paid back. In order to be approved for a loan the credit score is used to evaluate whether or not it is likely to be paid back within the terms of the loan. As a result those with bad credit have trouble getting favorable terms for cars, housing and basically anything that can’t be purchased outright. Does it negatively affect people for things outside of their control and perpetuate cycles of poverty? Absolutely, but it is based in actual fiscal risk to calculate sustainable loan practices.
China on the other hand took the US term of “credit” and abused the everloving shit out of it to punish people that the government dislikes. Did your cousin post a Xi Jinping Winnie the Pooh meme? Well too bad that you were shopping for a house, because your “credit” is no longer high enough to not be homeless. You should have thought of that before you were related to someone who disagreed with the government!
Not being able to demonstrate to a bank that you are financially reliable enough to pay back a loan is unfortunate, but a rational reason for an unfavorable interest rate or denial of a loan. Making people ineligible for even renting an apartment that is within their financial means because the dictator in charge dislikes you is a completely different thing altogether.