I agree that girls who have competed against boys learn a lot. Growing up in the 70s I had a little sister 4 years my junior.
Among my friends we used her as an extra guy to even up teams. She was playing against guys 4, 5 and 6 years older than she was. She ended up a stud athlete. Easily the best athlete in a family of seven and my older brother was captain of the swim team and I was captain of the wrestling team. She buried us.
Having said that, the scenario developing is not fair to girls. It's been shown repeatedly that between a male and female of the same size, on average, the male has 40% more upper body strength. The physical differences are stark. It's not what many of us had in mind when we supported Title IX. Girls can gain great experience from competitive sports, let's not drive them out of it.
I grew up with only brothers - and was proud that I could out run, out climb and out arm wrestle any boy my age - until I hit 13 - then my whole world changed...and I rather quickly lost interest in trying to 'out run' them.
I coached my youngest son's soccer team for a couple of years. It was a coed team for 10 and 12 yo's. At that age there was very little difference between the boys and girls in agility, speed and coordination. The best girl was as talented as the best boy, but the boys were more aggressive. A few years later and there was absolutely no comparison.
Girls sports will be influenced by this. So will scholarships. Girls who might otherwise make a team will not have the opportunity because positions will be taken by males who 'self-identify' as female. Accommodations are already in the works for 'intact' males who claim to be transgender to compete on female Olympic teams.
Transgender males are a very small percentage of the population - but at this point,
any male can claim to be...and sometimes the financial stakes are high enough to make a 'false claim' worthwhile. That's bad enough, but add in the locker room chaos...and no, it is grossly unfair to women. Wonder what happens when a female athlete accuses another 'female' athlete of sexual assault?