In case you were unaware, most cast iron anything is cast in sand. Engine blocks, skillets, you name it.
I was shocked to learn in the 80s that it remains, to this day, one of the dominant methods of casting iron and other alloys.
And there's a lot of science or technique that goes into it. What kind of sand you use, how often you change it, whether and for how long you tamp the mold before casting to compact the sand, and so on, that provide opportunities for cost-cutting and enshittification.
And some other things, like high-clay-content sand can make smoother castings. But the water content of clay molecules means they explode on contact with molten iron or other metals, which sends silica molecules into the atmosphere and creates silicosis problems for casting workers. And once the clay gets burned, like pottery, it goes from a fine colloid in the sand to big burnt clods, making castings rougher when you don't change the sand.
Also, one of my lifelong fascinations is the amount of technology (engineering and ingenuity) that goes into manufacturing even a prosaic, no-moving-parts item like a cast-iron skillet.