I have read a few books that address these issues. There are some chapters in the book "Outliers" by Malcolm Gladwell. He goes into eligibility rules around birth age for youth sports, and how the kid who is nearly a year older than some in the same eligibility year excels because of that and then gets additional coaching and playing opportunities compared to others.
There is another book called the "Talent Trap" that looks at the selection metrics used in youth sports.
I have seen many young players in ice hockey who excel in peewees based on size, speed and ability to skate with the puck. This actually stunts their development with other essential skills, like passing, vision of the ice, receiving passes. They can skate through 5 players and score at age 11 without looking up. When the other players are older and bigger and allowed to hit them, and they haven't learned the necessary game skills, they no longer stand out.
I think a key point often missed in youth sports is that winning the under 12 championship by 8 goals shouldn't be the primary metric. Excluding younger or smaller players at a young age inhibits development of both players and the sport itself.