Also there may well be areas of China where the virus never reached. I gather internal travel isn't massively widespread, and the severity of the lockdowns they imposed exceeded anything seen in the US or UK.
Also beware that there are reports of China having started vaccinations long before safety and efficacy results.
The flipside of exponential growth is exponential fall: In the best case if you can eliminate all social contact for 5-14 days the virus is essentially gone. But very few Western democracies are able to agree on super strict lockdowns, and if they do, they need their neighbouring countries to follow.
Individuals who don't care exist everywhere, but in China government can force them to do the right thing. In the West it can't do that easily. I guess it's the price of individual freedoms.