It's not even 2D with one eye. We can estimate distance purely from your eyes focal point.

with one eye you have temporal parallax, depth cues (ordering of objects in your vision), lighting cues, relative size of objects (things further away are smaller) together with your learned comparison size etc.

Nope. There are a number of monocular depth cues: https://en.wikipedia.org/wiki/Depth_perception#Monocular_cue...