Many employment contracts have equity components to them. As for "giving away what you produce" - no, you are agreeing to trade it for cash, not give it away. You basically imply that anyone trading work for cash is being exploited.
A capitalist system would collapse without workers, without capital, without a decent legal system.
Many people do work as one man businesses. It does change the nature of the relationship because the economy isn't a one way river. There are all manner of feedback looks - you mine copper, I buy your copper, make some electrical component, sell it to the manufacturer of a Komatsu, they make mining trucks, sell it to you. It all goes round and round.