> argue that China has sufficiently prepared for a fossil supply chain disruption of this magnitude

Where we agree is in China having massively reduced the impact of this shock. (And, probably, in them succeeding in insulating themselves completely within a generation.)

Where we don't is in this still being a stagflationary hit to China and, probably, a worse economic hit to them than it will be to us.

Put more succinctly, the first and second derivatives are massively favourable. But the actual level still produces lots of vulnerability. China will be better off than its neighbours. But it's still going to get screwed even if the war ends tomorrow, which it isn't.