The entire human race is only in existence because of outdoing its competition. Everything about us is keyed to rising above those around us. If you throw that out, you'll never develop at the same rate.
It might seem "uncivilised" to be riled at some twink coming in and destroying your strength or some guy lifting 15kg db curls with 19 inch arms (whatever incites you), but it is that streak of competitiveness that keeps you in check and ensures you stay strong and motivated.
I absolutely abhor competition in most of the realms of life and I can assure you, there is no question I'd have done a whole lot better had I not hated so much.
Naturally, that isn't a blanket thing, if you're rich, with a lovely girl and you already attained that body, enjoy life - for the rest of us, though, we need to grind and whatever keeps us turning up to the things we wish to strive in, works.