Efficiency is a Chimera.

those others are not involved in the exchange.

I’m not going to explain your own theoretical attempts in this thread anymore, let alone for it to be considered a philosophical attack would probably mean to manage to explain your own theoreticals without me having to explain not only my conceptions but yours as well. Doing the work for two people isn’t high on my priority list in this forum at all times.

good day.

And? They are still worse off.

Efficiency is a mechanical/physical concept - something can be more efficient with given inputs compared to given outputs. But it is up to us to determine the relevancy of input and outputs - their relative values. Especially as there are trade-offs between various inputs and various outputs, it simply makes no sense to talk about ‘efficiency’ outside of a tautological context of X per Y; a context which has no implications for decision making unless one already accepts that X is the desired good and Y is the only relevant cost - a situation which rarely faces real people, if ever.