You have two things that are measurable, the value that someone is willing to give for the product and the price that the worker is willing to sell his work for to his company
Both of these can be negotiated freely, so both the worker and the seller are willing to do the trade.
And you still don't understand that all Capitalists do is take portions of productivity of every worker, he doesn't help them at all, he exploits their bad position (needing $ to live)
This is NOT all they do. One person can build a small bridge. A big bridge requires many people. A huge bridge even more people. Organization of those people is hard.
And yet, there is no negotiation between the worker who creates the product and the capitalist. That is root of the problem, as capitalist is the only one that makes all decisions.
Wrong. I as a worker can demand/ask for a higher salary. If I do not get it I can go to a competitor. There is a marketplace of supply/demand out there.