One theme that is common to almost all visual art that strives for some form of realistic appearance is that they start out with real material appearances and physical lighting behavior. Both are inescapable parts of the reality in our physical world, anyway.
By extension, this means that it is highly desirable to have a renderer capable of reproducing the real world as a baseline for highly controllable aesthetic tweaks. When you look especially at VFX specific tools, they have - almost without exception - two layers of tools: the first creates a realistic simulation (e.g. water/fire/shattering...) and the second layer allows for tweaks to control the final look.
If you want something realism-adjacent that makes sense. If you want to create Antichamber, which is a game about non-Euclidean geometry, maybe not. You can carefully try to match up the lighting on both sides of an invisible teleporter, but it's going to be much easier if your engine doesn't try to do lighting at all. (Antichamber is mostly flat colors, basic flat shading, and hand-drawn accents)