Hard to not lose when efficiency gets compared with a well oiled clean roller chain.

A good mechanism for a pedal powered drive system, that application to a bicycle a bit kludgy, especially one with the fork backwards.

but there are lots of other machines that could benefit from a human power source

a flour mill, a water pump, maybe a pedal powered Forklift?
but thats 3rd world uses , or maybe this one when the oil goes away.