Fair point, but then that is why we look to provide more power than needed to cover such losses. While we are compunding the potential forces, the potential friction losses are compounding too. For, we must look at the yin -yang of both the efficiencies produced, and their inefficiencies too. For, at each conversion point/ mechanic, everything is broken into it's efficiency (power transfer) and inefficency (power loss, friction, cost of conversion).
But, even that has a flipside, for in lifting/ compressing jig this innefficiency/ friction stands against us. But, if controlled lowering/ extending jig; that friction now stands on our side, to allow control of larger load!
The main aim hear was to show the geometric increase in powers by a small change in way pulley systems are assembled, not to build one of these specifically. Like, how to take jsut a 5xRig, and get 8x out of it etc.