Growth can come from a lot of experiences. It is hard, but totally normal, to be very lonely at first. Many kids, maybe including OP, will spend their first week of college being surrounded by different types of people, and it can be helpful to have some prior experience with that. We can agree to disagree as to whether spending 72 more hours at a summer camp will ultimately benefit him. In any event, he likely decided already.
I think you missed the point about the potential benefits. An extraordinary essay can result from the most mundane of experiences-it did for the Oscar winner. It was not that his camp was anything special, it was how the story was told and how he chose to participate.