There are a bunch of studies that show that there is minor map advantage on most (not all) measures for trans athletes a few years after transitioning with hormone therapy. Some trans people never go through puberty of their assigned sex at birth.
I used to be of the view that it wasn’t fair for someone who was amab to have an innate advantage over someone else who wasn’t. However, we should also consider where they would compete. Is it fair to have trans women compete against cis males who now have a similar, but more profound, advantage over them? Or are they now just excluded?
I’ve come to believe that all sports at the elite level are dominated by those with genetic and physical advantage, usually by luck. Trans people also for in that category, but it’s easier to pinpoint the why for them. All the rules of sport are arbitrary, anyway.
So, after consideration, I think we should have sports open to all that are (identify) as a particular gender. For sports that already categorise by physicality (boxing, weightlifting etc), I don’t think it would be problematic to consider their physicality too. For many sports there is no advantage anyway, after transition. And even if there was, isn’t the point of sports to have fun, to enjoy oneself and have pleasure. Only a rare few people compete at elite levels. Excluding trans people hurts far more.people than it helps.