* CFCs are used in relatively few products. Greenhouse gasses are integral to how we get food, build, make gadgets, move around, and keep the lights on.
* There is considerable cheating on CFCs in China (source: widely reported)
What happened was that the rate of decline of CFC concentration slowed down[1] after 2012. This was an indication that there were new emitters. China then found the emitters and shut them down. [2]
[1] https://www.nature.com/articles/s41586-018-0106-2.epdf
[2] https://nationalpost.com/news/world/china-makes-arrests-shut...
> The findings suggest that China, which was thought to be the source of most of the rogue emissions of the chemical, CFC-11, has made strides in clamping down on illegal production of the gas. CFC-11 is used to make insulating foams.
-- https://www.nytimes.com/2019/11/04/climate/china-cfcs.html