How many 54 year old women can still play full contact team sports with opponents, in some cases, who are 30 years younger than them? Childbirth, menopause and caring responsibilities (which still largely fall on women's shoulders) are 3 pretty big obstacles.
I saw someone in a tweet reply offer up a link to an article about old (50-60) club rugby players, as some sort of attempted rebuttal to someone posing this question.
Every single player in the article was male though. No examples of older women...
I think the age profiles of lower-level male and female teams look very different, with female skewing much younger.
It's got to be much easier for men to keep up a sport at club level a their hobby after having children. I can imagine the drop-out rate of women who never go back is huge.
And maybe there are just more male teams, so there are 5th (or whatever) division teams for older men to play on - there probably is no equivalent female division.