I see that Inigo Quilez work is more in the "render a scene not necesarily in real time" realm. Like, you could make a raytracing program, make it render off camera a shiny scene, and only after rendering it shows you the image.
Because of this, its very suited to math and procedural generation. You just change some parameters, render and show. Games instead have to do this in real time, with less latency and CPU/GPU usage. And procedural/math generated content tends to be CPU heavy (more usage+latency), if not also on the GPU (cant be cached, etc).
Shaders are more on the middle of this, because you want to apply certains transformations to and from rendering data.
Because of this, its very suited to math and procedural generation. You just change some parameters, render and show. Games instead have to do this in real time, with less latency and CPU/GPU usage. And procedural/math generated content tends to be CPU heavy (more usage+latency), if not also on the GPU (cant be cached, etc).
Shaders are more on the middle of this, because you want to apply certains transformations to and from rendering data.
Just my armchair observation.