Ideally, your kid has done what they wanted to, not what they thought was what colleges wanted. The kid who played one sport year round on an elite club team and at,BS and who realizes that their quality of play isn’t what it needs to be for their top choice schools, has made a choice to prioritize the schools over the teams. Other kids might put teams first. Some might have had a temperament that wanted to do ECs in addition to sports. If what they chose was authentic, it’s fine.
While an AO doesn’t want to read about a sports event (gosh, how many info sessions advised against this), it’s fine to write about being the kind of person who does things immersively (the serial monogamist approach to passions) or who discovers something about themselves and the world through connections with teammates. But it has to be about who you are, not you the player or the sport.
Maybe something in the decision to not continue was important to personal learning. Any of those things are as fine start for an essay. The essay is simply about who you are.