There is a lot of fossil fuel development going on that doesn't make sense if renewables are cheaper. Especially in China where panels are actually made. I'm open to an alternative explanation, but I don't think it's inertia. Most industries switch to cheaper tech pretty soon after it becomes available.
https://www.scientificamerican.com/article/china-says-it-wil...
China is starting to move in the right direction, but there's a ton of planning lag. China is by far the largest single consumer of solar panels. It also deploys more wind turbines than any other country.
Two limiting factors are China's insatiable need for ever greater power generating capacity of any kind, and the surprisingly rapid uptake of renewables globally which has constrained new production.