In socialistic systems, isn't there a natural tendency towards central planning? I don't see how in practicality you could have everything be owned by decentralized councils of workers. How will the people at a steel mill for instance know how much to produce and be able to exchange that for living necessities? If there isn't a central planning, wouldn't there inherently need to be a market mechanism? What would the currency be?
If there is central planning, doesn't that de facto create a class system where some group controls the means of production by dictating how they are to be used? What variable do central planners optimize for when creating their plans?