It’s already here, it’s been here for a decade, renewables are a mature industry. They’ve already effectively destroyed the economics of coal, and natural gas is next.
But as of Jan 1 2024, they also had to introduce a financial incentive just to keep coal plants online, because otherwise the coal plants can't compete on price, just like you said! Some weird economics going on here, but it seems like China is still adding coal just to maximize total power deployed, even if it's uneconomic at the margins.
https://www.reuters.com/world/china/china-guarantee-payments...
Batteries with renewables are already cheaper than nuclear and it will only get cheaper while nuclear costs are ballooning.