I don't buy for a second that the wages absent a union are what a free market would predict. A free market requires freedom to participate, and most individuals

I don't buy for a second that the wages absent a union are what a free market would predict. A free market requires freedom to participate, and most individuals are forced to sell their labor in exchange for food and shelter, let alone necessities like healthcare. Unions provide a framework where something closer to a free market wage (note: this is to say nothing of the morality of using markets for these purposes, a separate question) can be negotiated. Maybe in a world where people had a UBI they could live off of this could be argued, but that's not the world of today. You're cherry picking free market economics only where it suits you. Your assessment of antitrust law is also pretty far removed from reality. By that logic, mergers and acquisitions would be illegal in every instance. Or, for that matter, standards bodies. Corporations band together to increase profits all the damn time, and the overwhelming majority of this activity is legal.