And of course average is not good enough for an electric grid, the variance is highly relevant. As my statistics professor used to quiet: if your left leg is standing in liquid nitrogen and your right leg is standing in boiling oil, you are enjoying a perfectly comfortable mean temperature.
Variance matters. A lot. In an electric grid, you need to be able to cover minimum requirements even when solar and wind are having a bad day or night.
China got their solar industry financed by German subsidies, and they have plentiful deserts with lots of sunshine. The Gobi desert is the place on earth with the most sunshine hours, apparently more than the Sahara(!). It would be insane for them to not take advantage of that to reduce their use of coal, now at what, 65%?
But they also apparently think that safe, reliable and cheap nuclear energy is an important part of their energy mix, otherwise they wouldn't be planning on tripling their generating capacity, would they now?
If nuclear could compete, China would be building the hell out of it, and selling it internationally. Getting other countries to use your nuclear supply chain for their electrical infrastructure is such a huge geopolitical win that if it were possible, it would be one of the key political and economic strategies of China.
If China, one of the few countries with a mastery of large construction projects, can't make nuclear cheap, what hope do more advanced economies have with their higher labor costs?