This is an interesting debate. One that I think will eventually have the Supreme Court decide.
I agree with the competition level, especially at the younger ages. Is an 8 year old “transgender” kid, really transgender because they identify as the other? Many sports are coed at that age anyway, so shouldn’t matter.
When they get older, especially after puberty, that is really the issue. This is extremely evident in sports like swimming, running, jumping, weight lifting or other where there are set measurables. A good HS boy is equivalent to an Olympic level girl. Regardless of hormone suppressing or whatever, there are just so many other factors. The man lungs, bone structure, muscle mass and other is just more than a woman on average. In my opinion, there should be no biological born male competing in a female division in competitive level sport. I think a good thing that Trump signed the EO, which gave the NCAA and others some sort of legal backbone. If not, they would brunt the legal costs of challenges. Which as noted, I think this will end up with the Supreme Court deciding.
I have a daughter who has played multiple sports at a rather high level. She has yet to compete against any trans athletes that I am aware of. There have been some that looked rather masculine. Of any sport she has played, she has yet to shower with any teammates or opponents. I imagine there might be some teams that shower together? She will be competing the next four years on a D1 scholarship. Her showering with a trans athlete is on my list of worries, right below the moon falling out of the sky and Chuck Norris wanting to eat pudding out of my ear.