Comparisons are destructive, fuelled by antagonism of self or others.
Competitions are done when all competitors are knowledgeable. Everyone is aware they are competing at a particular time and can prepare accordingly. The outcome of a competition can be saddening or disappointing, but a party can leave knowing they did their best.
However, the outcome of a comparison is belittling & demeaning. It is forcing some party to live up to the way another party conducts themselves — it hails one party’s manner as the “good” be all and end all, whereas competitions have fixed variables and an independent metric with which to assess the participants.