Contestants arrive at the contest to see who can fly the best that day or set of days.
Each pay some nominal entry fee and must belong to some organization. If you do better than the others in your division, you get a trophy of some sort to clutter up your shelf. Interesting, but the main motivation should be improving your own flying . If all the other contestants are poor fliers that day, your 1st place trophy means nothing. In each division you are trying to show how your own flying abilities are improving.