Comment by WorldMaker

It's not a terrible description of what Borderlands complex web of shaders are doing. A base layer part of it is effectively a cell-shader, but Borderlands is doing more other things, too.

Relatedly, cell-shading and other shaders are sometimes very heavy GPU compute workloads (which would also be far more expensive if they needed to run on the CPU due to a bad graphics card or driver). It seems funny to dismiss cell-shading as "not super demanding", when cell-shading was a technical dream or expensive technical demo thing to do for quite a while in the time before modern GPU shaders.