@freemo @avlcharlie Well, if one person also cannot own another do we also not have a free market regarding the ownership of resources, and thus real capitalism requires literal slavery?
Or, to be less socratic and more precise about the argument, in the market worker cooperative system all resources (tools, raw materials, outputs) can still be traded between worker cooperatives. The only “resource” that is not tradeable is ownership over the enterprise itself, and if you want to make a case for why this is bad you would have to go beyond “markets allocate resources efficiently” and into why this specific thing should be treated as a tradeable resource (like e.g. people shouldn’t be, which is why the previous paragraph). That is, you have to argue for private ownership of means of production being important into itself, which is why I’m saying this, and not markets, is crucial for capitalism. (I’m not saying at this point there are no arguments you can make for that, just that this is a different thing than just arguing for markets.)