Of course selective college admissions is a competition. Since there are more applicants than spots available, and the adcoms will choose who gets to fill those spots based on the performance and attributes of the candidates, the candidates are most certainly competing with each other to put forth the best package of performance measures and attributes in order to be chosen.
The best analogy of college admissions to athletic competition I can think of is the example of the Olympic Trials. In track and field there are three spots per event available on the Olympic team. In the Olympic decathlon trials for example, each of say 20 guys entered in the decathlon puts together their best performances in 10 separate events over the course of two days that are added up to a total score. The three with top total scores are “admitted” to the Olympic team and get to go to the Olympic games. They won the competition. They were ranked 1, 2, and 3 by their scores, but those rankings among the top 3 don’t matter too much at that point, because all three achieved their immediate goal of making the team. That’s why you often see the 3rd place finisher at the Olympic trials act just as deliriously happy as the first place finisher.
The other 17 candidates? They were not “admitted.” They lost the competition.