That’s one of the main fallacies of capitalism apologia: assuming that the market is free and inherently fair.
In reality, the “market wage” is the lowest amount that the company can possibly get away with while retaining its workforce. Conversely, the market price for a product that workers buy is the HIGHEST profit margin possible without hurting sales and the number one priority is always profit for owners/shareholders.
As for the market being free, that’s literally impossible: without the presence of government regulations and unions to constrict them, the most powerful forces constrict the less powerful.
You either have tyranny of the already rich and powerful corporations or limits to their freedom being imposed. The American system leans heavily towards the tyranny end, which severely stifles the freedom of workers.