Because value is a combination of human labor AND the means of production and the means of production aren't owned by working people. I can start making cheeseb

Because value is a combination of human labor AND the means of production and the means of production aren't owned by working people. I can start making cheeseburgers but McDonald's owns the efficient equipment, the marketing, the good locations to sell them, etc. such that I can't possibly make profit outside their system. So I'm forced to essentially rent space in their kitchen in order to be compensated.