I'd say it's only beneficial if it leads to improving yourself (in the case where you are comparing yourself to someone who is "better" - for whatever metric) -

I'd say it's only beneficial if it leads to improving yourself (in the case where you are comparing yourself to someone who is "better" - for whatever metric) - or if it leads to improving the life of someone else (in the case where you are comparing yourself to someone who is "worse" - again, for whatever metric). Of course, in the latter case, you should consult with the person to make sure whether they want their life improved or not (maybe they are content with where they are at, or they want to achieve better results on their own without someone's help)... It would only be detrimental if the outcome of the comparison was doing nothing but complaining, without taking any action or research to understand or figure out how to better oneself (or to merely sit around and congratulate oneself on how much better you are than others - conceit or arrogance isn't all that great for a person to indulge in, but that is merely my opinion). As for why we do this - well, this has already been answered by others, I think.