It doesn’t matter how “hard” you work, but the value of the work - and value is 100% determined by how much people will pay for your output, and that price is determined by the scarcity of your product.
A guy that digs gold out of the ground is going be able to sell that gold at a higher price than a guy digging worms; while working at exactly the same “hardness.” There are those that would suggest that both should be paid the same, which is ridiculous as that suggests a pound of worms is as valuable as a pound of gold.
Sure, that's how the system works, and why it works well in order to make sure gold gets dug out of the ground rather than worms. That makes it a justification for doing things this way, but it's not a justification for me, personally, feeling entitled to the money I receive.
A guy that digs gold out of the ground is going be able to sell that gold at a higher price than a guy digging worms; while working at exactly the same “hardness.” There are those that would suggest that both should be paid the same, which is ridiculous as that suggests a pound of worms is as valuable as a pound of gold.