The combination tends to work well.
True as long as you have good grid connectivity so you can ship wind power in from a distance, which China is also building. Dealing with these variable sources is getting better and better. Storage over 24 hour periods and possibly even weeks also seems to be moving towards being a solved problem with new technologies coming online. Find a mineshaft or a hill, lift a weight from the bottom to the top, then store it nearby. Lower it down when you need energy back. Alternatively, pump water out of an underwater concrete dome or pump water up a hill and so on. It's also possible to convert iron oxide into iron powder that can later be burned for energy. That's all before you start talking about more expensive but convenient solutions like batteries.
China will now have a vast amount of energy that they can start testing those solutions on as well as finding industrial processes that can run intermittently when there's super cheap energy available. That converts this from a tactical gain into a strategic one. Once those industrial processes are mostly based in China they can keep learning to optimize them at scale in a way nobody else will be able to.
When we look back in 30 years time at what caused America to fall, energy prices, spending too much on nuclear, and failure to compete in renewable energy is my best guess.