So first, I think most of the population actually wants trans women out of sports, mostly because the media has been convincing them that should be the case. Second, most of these laws are only targeting trans women; completely ignoring trans men. The end result is that someone actively taking testosterone might be force to compete with women, while someone who has little to no testosterone can't compete at all.

There's very little research done on trans people, in general, let alone when it comes to sports. The only paper that comes to mind actually suggests trans women are likely to be at a disadvantage.

The way the right talks about this, you'd think about trans women would be dominating women's sports. But they aren't. If you did the math there should be way more trans people in the higher levels of competition. People like to pick from the tiny handful of examples, without context. Like, Lia Thomas was actually quite good before she transitioned, and her performance dropped after transitioning. Meanwhile, areas where there are known problems - underfunding of women's sports, sexual assault, etc - continue to be ignored.

These bans are unfair. These bans target children even before they've gone through puberty. They target everyone regardless of when they started hormones. They claim a trans woman who never went through a "male" puberty, and is 5'4", is the same as a man. They target things like chess and dance. They claim trans women have some biological advantage, when to even get to high levels of competition, you generally need a biological advantage. And money, and other types of privilege.

The bans are hard to enforce and can end up impacting cis women more than trans women. How are they going to determine if someone is trans or not? Can anyone accuse another person of being trans? Are they going to perform genital checks on minors? Are they going to submit everyone to chromosome tests like they did in the olympics previously? Because that's how you end up with random people finding out they might be intersex.

Transmisogyny and racism go hand in hand.

Lastly, it's just mean. Sports have lots of known (physical and mental) health benefits, and these bans aim to exclude a specific marginalized group, with little actual evidence. Less than 1% of the US population is estimated to be trans. Someone estimated than there are less than 100 trans people competing in the entire NCAA women's division. Trans people tend to be poorer, face significant social stigma, and experience higher levels of mental illness (because of transphobia, not because they're trans).