Why are "elite" women better relative to "average" women? (Vs. men)
Or why are "average" women worse relative to "elite" woman? (Vs. men)

This seems to be true in all sports.
For all ages of females.

Theories and what might be done if each theory is the cause:
1) A smaller percentage of women take sports seriously.
It seems unfair to penalize more serious men because there are more of them.
(Set standards using age/gender graded percentages.
2) Women and girls have more responsibilities. They are doing there fair share of society's work AND ALSO picking up slack for idle men who waste time with sports.
This would make it unfair if women were expected to age the same competency as their idle husbands.
(Set standards as a function of numbers participating).
3) Grester hormonal variation- the ratios and quantities of estroge, testosterone and other steroids is more variable between women and more variable for an individual woman.
This would also make it unfair to expect women to have the same % of age/gender graded performance.
(Set standards as a function of numbers participating).