I remember reading last year about a declining rate of young people getting into competitive swimming. (Article referred to the United States but I suspect a similar trend, at least in what was referred to above as the anglosphere.

The article was non-scientific but the writer theorized that it was due to issues with body-consciousness. The writer discussed alot of ways the body issues young women face make them disinclined to wear a swimsuit. Didnt go into depth with young men; is a funny omission given that I expect the average young man is more nervous about wearing a speedo than a woman would be wearing a one-piece suit.