Building a complex universe starts with two words. 

"Space" and "Navigation"

The human brain builds a finite model of an infinite universe, and we get to experience that through the process of perception. It does this through a complex set of grid and head cells that map to orientation and position within space.



Within the hippocampus, grid cells are organized in a hexagonal pattern. Similarly, in our natural environment, bees store honey in hexagonal matrices for maximum efficiency. The hexagon is the largest object that can be tesselated (multiple instances can be fit together perfectly without gaps in space.) I guess the universe seems to think that the hexagon is superior to the cube. 

Next steps

How do we focus on elements in the distance while being able to see closer elements, when we're obviously going to have too many triangles? Well, we manage the level of detail as the camera moves around the planet.