Do you have any idea how close a tolerance you must have in order to have millions of bricks and have any pair of them mate cleanly, easily, and with sufficient clutch to not immediately fall off? And have multiple "legal" connection locations on each brick? And permit multiple bricks attach with equal spacing and equivalent strength?
We are talking a process capability that rivals, if not vastly exceeds, most aerospace manufacturers. No disrespect to the rocket science guys, but we are talking tight tolerances on small parts.