Another side of the argument goes back to the fact not everyone wants lifelike/realistic graphics. Orbus was the first game I ever purchased for VR and only the second that I owned. The first was Fallout 4 VR because it was free with my headset at the time. Fallout was so realistic that the first time a giant cockroach flew at my head, I shut the game down and uninstalled it.
If Orbus had touted itself as having “realistic” graphics, I never would have picked it up. I like the graphics style of Orbus - I don’t think raytraced shadows and reflections would really fit in with the style of the game. GTA makes a bit more sense - they’re aiming for a fairly realistic set of textures.