If you see force as a volume in a pitcher of distance x power; you can either spread that volume tall (high back pressure tension) but not far, or spread it very thin(lo back pressure) but far, but must always equate to the same volume amount.
A 3:1/zRig pulley rig allows you to pull 1 end to shorten 3 lines at the same time. So need to pull 3 feet of line to move load 1 foot, so get 3x as much tension return. Same volume of force, but only 1' rather than 3' to 'stack' that volume into, gives higher 'backpressure' / tension.
Nick's rig looks trick, would imagine has high efficient pulleys, last 10% or so efficiency can be expensive. Also, notice, the banjo shape, that allows the lines to run as inline as possible and not 'scrub'. Rope only resists/ conducts force on the inline axis, and only in tension direction. Chasing 100% efficiency, totally inline force etc. is the holy grail. Also, might have lock cam on side, to hold tension, allow impacting etc.
Nick's top pulley has 5 lines to it, if no friction and pulled free end at 100#, top would have 5 100# pulls on it, so is 500#, so is 5:1 pulling down, then likewise on lower; has 4 legs of pull, if all tensed the same, get 4xReturn/ pull on anchor etc.