That’s not true. Many companies people work at provide them little to no incentive to work harder or better, yet still a lot of people try to do so. Lots of places have almost no possibility of promotion just the ability to go elsewhere. Some professions like teaching, nursing pharmacy treat all workers as interchangeable with no performance incentives.
I can tell you that there is no way I’d be doing what I do if it wasn’t for the money. I’d be developing useless keyboard firmware or some other junk no one but me would care about. It would provide minimal value to the world.
Who pays nurses more just because they are good? In a lot of professions rates are set by governments or institutions and there is not enough competition between businesses for wages.
Any private clinic would pay the better nurse more? You can check this quickly on job-listing portals – nurse wages are in the 20000-100000k/year range, so clearly supply and demand as well as qualification are determining it. Which socialist country is it where wages are ceiled by the government?