We are able to set BillboardGuis that render on top of bricks and walls, so why can't we do that with bricks? With that, we would be able to make 3D Gui elements, for example.
No, I literally mean parts that render over top of other parts, even if they are technically behind those parts in 3d space. It's a strange concept to grasp because it never happens in real life, but it is used all the time in games to make 3D GUIs.