It’s not about the “regulatory environment”, which is almost irrelevant when talking about China. What’s driving this is state-led development with clear goals, like reaching peak carbon by 2030, a claim which they can actually back up with developments like these.
IMO Xi/PRC is a little bit TOO magnanimous about enviroment / eliminating carbon. While US continues to increase (and now lead) in oil/lng exports, PRC is leaving good money on the table not building 1000s of coal plants abroad or exporting their centuries of thermal coal stock. That's the kind of irrational behaviour you expect from someone that cares about enviroment.