When my daughter was in elementary school, she played competitive soccer for a season, having loved her recreational league. There were too many girls for one team, but not enough for two teams, so she and one other girl were placed on a boys team. That experience killed her love for soccer and they both switched sports the next year. And this was U8! She’s always been competitive and athletic, but the boys played much rougher than she was used to. It wasn’t fun for her. Post puberty is so much worse.

The center-right outlet The Bulwark once again allows a tiny bit of light on the subject. Thanks, "Lia" Thomas!

Jonathan V. Last eviscerates the idiotic Atlantic article advocating the abolition of single-sex sports, calling it "bollocks from top to bottom". After pointing out that the consequence would be the near-elimination of women from competitive sports, he talks about different ideas of "inclusivity". He notes the irony of "progressives" advocating in this case for the opposite of their usual policy preference:

The irony of the progressive view of inclusivity is that making sports in America co-ed would be the most libertarian, meritocratic solution. The solution that takes nothing but outcomes into account.

And the effect of adopting such a culture would be the elimination of most of the opportunities for most girls, in every sport and at every level.

We might think gee, what a coincidence, all of a sudden when women and girls as a class stand to lose, the lefties go all libertarian all of a sudden, wonder why. But of course Last, being respectable, and male, doesn't go there.

There is nothing libertarian about letting men play in Women’s sports

“Meritocracy” is a stupid argument. Letting men win Women’s sports is not about merit. It’s being outside of one’s specialty

If that is the case then adults should be able to play in children's sports.

Professional players in high school and college sports, etc