Again, I'm not arguing that China is doing extremely well regarding CO2 intensity of their electricity. My point is that they perform pretty on par with most comparable countries.

Looking at CO2 per kWh (a much better metric if you want to boil country comparisons down to a single number) you will find that they are not doing significantly worse than most nations in their weight-class (GDP wise), and in fact doing better than quite a few.

Australia, South Africa, Poland, India, Indonesia and basically all of the middle east is doing worse than them. Even rich nations with heavy renewable commitments like Germany are barely 40% lower, and this is frequently negated by higher per-capita electricity use (like it is with the US).

In my view, not many wealthy western nations are actually in a position where they can demand significant improvements from China in this metric without getting laughed at (except France, Scandinavia, Spain). If you look at nations with more than twice the GDP per capita (and a headstart in development) it is more than reasonable to demand that they be at least below 50% of (current) Chinese CO2 intensity (in my view).

I strongly believe that we see so few actual demands in this regard (and so little progress in more direct CO2 taxation schemes) because most nations realize that they live in a figurative glass house. E.g. if the whole EU was at french emission levels, we'd be much more likely to see import tariffs linked to metrics like this, effecting improvement all over the world. Pointing the fingers at China on the other hand is neither accurate nor effective.