I feel that sports are a great addition to the maturation process for any child capable of playing. But where a child plays is equally as important as the sport itself.
Some leagues are geared to be competitive. Catholic school sports (in my area) are the first that come to mind-especially in the middle school years. Their goal is to win each game and play the best players in order to achieve their means. Systems are taught but all players aren’t “developed.” The players that coaches concentrate on are the ones again to achieve the final goal of winning. It seems to me the development of a player is more in the hands of the parents. This was true when I was young and I haven’t seen evidence to the contrary.