Any value assigned that is not due to productivity is arbitrary. Only a socialist thinks that one can JUST DECIDE, based on need, what the value of a job is. So yes, it IS arbitrary.
I do not know what universe you live in, but in the Real World, hardly nobody gets a wage based on their productivity unless they get a commission, or are paid by piece work. I mean, who would even decide such a thing? The higher up the totem pole people are, the more they think they are worth, but it has been my experience that most of the actual work is done near the bottom ranks. I think that you are living in Theory Land, but at least you will have lots of company!