Most people believe that merit should be rewarded with higher pay. But doing that in practice isn’t simple. Measuring merit to reward it is hard, especially in teams.
Random factors beyond one’s control can make one look productive regardless of effort, or ability. Furthermore do we believe in reward innate ability the most, or effort, or both equally?
This highlights a lot of the issues.
Yet another issue is the production usually happens in teams in one way or another. How do you judge the product of each each individual member?
I think the many factors that affect production and many not under one control are a reason we usually choose to redistribute wealth either in guaranteeing minimum levels of well being, or outright trying to make the gap from the most wealthy to lease smaller.