I wonder if same could be done to games. How much unnecessary work are modern games submitting to the GPU?
Hey, first author here. I do think we could apply a similar formal analysis to games, but this is complicated with the inclusion of depth and perception. This is not a concern in 2D rasterization for web browsers. The target for this sort of analysis would be the scene-graph, which describes how all the various objects are represented in a game spatially, and then you would somehow reduce the scene-graph to 2D modulo the view-port/camera of the game. This is much more complicated than what we did for Skia.
Game development has apocryphal stories aplenty about inefficient designs--e.g. the thousand-polygon model of a screw used on every rivet for every crate, or making a ship-in-a-bottle by taking a full sized pirate ship model and scaling it down to 1% size. Usually the solution is just to stop doing that.