We use way more information than just binocular disparity to construct our stereopsis. Since we extensive experience in our environment, we can use relative sizes of known objects, atmospheric blurring, occlusions, we can move our head and see the apparent shifts of objects, etc. The triangulation provided by our two eyes is not the most powerful of our methods to estimate depth.

These techniques are very hard to reproduce, however. Artificial 3D sensors lean pretty heavily on some sort of triangulation, because it can be formulated mathematically.

Perhaps they have a stronger Monocular Depth Cues part of the brain to make up for it