I just can't wrap my head around a people collectively happy with a pretty oppressive government.
Wrap your head around how oppressive the US is for, e.g., black men, or Muslims, and how happy white evangelicals are about it.
Rather, historically when things go off the rails in china, they go off the rails hard and they have a very long history of that to look back on, an order of magnitude more than the US's. From what I've seen, that's what's taught to them in history class. Conformism/capitulation => stability and safety whereas in the US conformism/capitulation => being a British subject/slave/native on a reservation/interned Japanese/and on and on.
Tl;dr: the differences in historical context are vast between the two countries
Typically I hear, "but the CCP lifted a billion people out of poverty!"
As of when? I know some people who left China in December on a tourist visa to another country.