Because “free markets, competition, being voluntary” are propaganda by capitalists using their owned media and purchased government to make its victims double as its defenders.

The goal of market capitalism is to end competition often by buying out up and coming rivals to kill the threat, manipulate the markets to your advantage using anything from bribery to cost benefit analysis of potential consequences/fines for sociopathic actions to potential profits, and conspire with your economic sector to coerce the workers you need into accepting less.

This is just expanded indentured servitude with a marketing team.