> I would always describe Overwatch (to take a gaming example) and Zootopia as "simple" graphics.

I think an art director would describe them as "readable". When there's a lot of detail and quick motion, it's important that the audience can very quickly recognize what they're looking at and what's happen. Otherwise, it just turns into a big jumble of chaos that the viewer can't follow, like in Michael Bay's Transformer movies.

A big part of the art of movie making is telegraphic a sense of rich realism and complexity while still having everything clearly visually parsable. Doing that when cuts and action are fast is quite difficult.

Doing it well affects every level of the production: the colors assigned to characters so they are separated from the background, wardrobe choices to also keep characters distinct, lighting, set design, texture, animation, focus, the way the camera moves. It all works together to produce one coherent readable scene.

A nice example of this is shown in Figure 2 of the paper "Illustrative Rendering in Team Fortress 2" [1] from Valve. It shows how they tried to make the silhouettes of each character class distinct and readable. (And the paper also discusses the choices that went into the color palette.)

[1] https://steamcdn-a.akamaihd.net/apps/valve/2007/NPAR07_Illus...