The labor voucher doesn't take the form of money, yet it still represents a unit of exchange used to appropriate products from the common stock, ie currency.
Who assigns the value?
Not all labor is equal in value. That's what I am trying to tell you. The cost of goods must equally be tied to the value of the labor required to obtain or produce those goods. Otherwise, it is not fair.
The dude who sweeps the floor is providing a service that can be performed by nearly every person, young or old. It is of little value compared to other forms of labor. The supply of floor sweepers is practically limitless. If all labor is equal in value, why would anybody bust ass in a hard or stressful job? You could just sweep the floors and live ghetto fabulous.
You cannot ignore those value discrepancies.
Why?
Because, by their nature, people are lazy, greedy, jealous, envious, etc. (7 deadly sins) and you cannot suppress human nature, no matter how hard you try.
Take everything back to the barter system and it becomes obvious that an economic system must be based on the natural value associated with goods and services, which is directly tied to supply and demand.
Capitalism
is the absolute best system, without question. If you want to tweak it here and there to prevent smart people from taking advantage of idiots, fine. I get it. But, capitalism must be the basis of a healthy economic system.