If it was purely about money, major league sports wouldn’t be spending millions on their players.
Sports is about entertainment. Entertainment is about money.
The sport has to be good, with talented players to make it entertaining.
In the case of the Trans male Swimmer, they competed as a male and got slaughtered constantly. This person on a olpmic level is a bottom tier competitor who you have as backup. The person as a male, constantly finished in the lower half of their bracket. THEN transitioned to female, and immediately started dominating her competitors. This person only wants to be the best in their league.