thanks for the tldr.
If an employee loses their job, they lose 100% of their income, and for many they are unable to survive this. If an employer loses an employee, they only lose 1/n of their production, where n is the number of employees they have. They can handle that reduction while they look for a new employee way more than the employee can.
That is what prevents the market from being efficient.
The problem is, nobody really wants labor markets to be efficient. Efficient labor markets mean that we would pay workers the subsistence wages, because, why they should be paid more?
That's the thing, labor is not like other commodities, say apples or computers. You want to make the price of other commodities to be as low as possible, and everybody (all humans in society) wins. But for price of labor this is not true.
The rate would be set based on competition with other employers for employees; you pay enough to keep a worker from getting a job at another employer.
So the answer to the question, “why would you pay more?” is, “so they don’t start working for someone else instead”
Now, the market system doesn’t work for employment because of the reason I stated in my original comment, but it isn’t related to the ‘minimum wages needed to survive’
The power of monopolies is actually inversely proportional to the "supply" of such entities.