Well, quite!
Women’s categories exist precisely so that women aren’t continuously overlooked/excluded in a male-dominated world, whether that be in Arts, Sports, Academic Scholarships whatever.
Permanently having two sexed categories has the reasonable side effect of preventing an over-correction and avoids the new issue coming up in some sports (eg marathon running) where both the men’s and non-binary categories have male-sexed winners leaving ‘non-binary afab people’ out in the cold.
Just accepting that ‘these 5 men were better than ALL the women this year’ would fuck women RIGHT OVER, imagine a sports world that looked like that?