The point was not about need but fairness. By total GDP alone, China could certainly fit whatever criteria to be included in the list of rich countries - but it seems that it's understood that this isn't particularly fair.
Likewise, the rich countries on the list have had over a century since their respective industrial revolutions to take advantage of it and use it to accumulate the wealth needed to go green. China, however, would have to change much faster than the rest. This is the unfairness being addressed (as opposed to need), and the credits were just one idea to address that.
When did China surpass the US to become the biggest emitter? I thought that wasn't going to happen until 2050, as per https://www.washingtonpost.com/climate-environment/interactive/2023/global-warming-carbon-emissions-china-us/
I'd dispute that China has no interest in reducing their emissions. See this other post by the OP, https://slrpnk.net/post/14732947 showing that they're on track to reduce their emissions this year.