Not an expert, but my understanding is that the challenge there is that a big cost in industrial production is the initial capital outlay for the equipment, and oftentimes to pay that back reasonably, you need to run the equipment nonstop. Also, some processes are challenging to stop/start.

"summer mid-day also has the highest electricity demand all year in many places due to air conditioning,"

Peak electric demand is 3-7pm in the summer. You might think you could then just set panels to to optimize for afternoon, but especially in winter, you get a big peak between 6-9am.