China’s problem is geography and density: they have plenty of ideal land for solar in the west, but people largely live in the east in tall apartment blocks in cities that are often cloudy. They build lines to send the power east, but can only build so much capacity per year while the problem is pretty big.

I reckon more Australians live in SFHs than apartment blocks (so have roofs where personal solar makes sense), and the major cities get more son than eastern Chinese cities do.