Your brain isn't able to compensate for lack of depth perception by judging distance and depth based off of light and cast shadows when there are no shadows, or when everything is in shadow. You're just missing vital bits of information at that point.

Yes it gets much more difficult to get around at dusk.

Somewhat. For example, side walks having a abrupt uneven drop or car entrances will appear as flat normal sidewalk at night. Canes help the situation. Flashlights aren't what they used to be.

Beds are also weird like that. I position myself against a wall so I understand where my bed ends and the floor begins.

Also cups are a real pain to place in a dim environment. I've said " I swore there was a table there " to many times. Poor wait staff.

Oh yes, my depth perception is all messed up. Sometimes I feel I do have depth perception, sometimes, I end up doing so foolish things that I doubt if I have depth perception. I just avoid dark and poorly lit areas these days. If not that, then carry my lights with me.