The reason is that the work God enables you to do for him is a gift. A gift to you, first of all.
This is why it makes no sense to compare. Why would we begrudge that God did not give us a gift intended for another? It wouldn’t fit. It would be like giving size 8 shoes to someone who needs size 10.
It is not that one size is better than another, but that one size fits one person rather than another, so that the full spectrum of God’s varied grace may be displayed.
(Note: If you truly want to excel, pursue love and seek to “outdo one another in showing honor” [Romans 12]. Love is the competition no one loses.)