...because living in such competitive arenas is liable to disappoint a man as time approaches.
Competition is not always bad, it can also have a good effect on an individual who turns it for good. Competition can be a driving force for development and growth as you see from businesses.
If you stay in a competitive area, it can motivate you to become better and develop yourself to be the best. Staying in a place where you feel less motivated or feel like you are the king is not good because you become too comfortable and something close to what we call a "local champion".