Unionism is capitalism. If you are a W2 employee in the United States, you are in a contractual relationship in which you have very limited leverage to negotiate and limited protections.

Humans organize together in many different ways for many different reasons. Your own assertion belies that — if my negotiating my terms of working for someone is crime against humanity, why should the guy controlling the capital have that right?

The dude for whom I work is worth $10-15B. What should he make for the benefit of humanity and efficiency? He negotiated a deal with the board for his comp.