Fair from the perspective of the person doing the work. I'm using the dictionary definition of "fair" here: A fair exchange is an interaction or agreement where both parties feel they are receiving something of equal value for what they give, resulting in satisfaction and balance rather than resentment or guilt. I'm not using the "living wage" definition, which is a phrase that's not related to the definition of the individual words that it uses.

If they didn't find the compensation fair, for their effort, they wouldn't do the work, and would do something else instead. You want to see positions that that are at the boundary of "fair"? They have incredibly high turnover rates, because people think "this isn't worth it" and quit. Where I am, fast food is a great example of this, where the companies weren't paying wages people wanted to work for, leading to unsustainable turnover, labor shortages, then pay increases.