Don’t follow the sport but from many years gone past it seems women excel at a very early age.
As they grow older, gain weight and fill out, it appears that maturity works against them in the sport.
Nadia Comeneci was a monster gymnast at 13. She never regained that height again.
A good observation. In the world of figure-skating, there's an infamous (in some circles) Russian coach named Eteri Tutberidze whose training regimen has the reputation of finding the youngest stars at an early age, and training them in such a way that they either win it all by 16 years-old, or burn-out by the age of 17