None of what you said is relevant to the core point that labor compensation is determined primarily by substitutability. As for why we "accept" that, it's because it makes rational sense. Why would anyone offer more to someone to do what someone else will do for less?
In your fictional utopia, you would need practically every single company in the world to agree to pay labor in excess of the rate dictated by market forces. Any company that deviates from that would have a considerable competitive advantage and quickly usurp its market. This is so categorically obvious that I hesitate to call it economics. It's not even just human nature. This is so self-evident that it may very well be a bedrock principle of sentience.
