I think the biggest tell when it comes to people mad about trans women in sports, is they aren't also mad about trans men in sports. In fact, they have no problem with forcing trans men to compete with cis men, but they have a whole ocean of crocodile tears ready for cis women being "forced" to compete with trans women. Why the asymmetry? Because they want to pretend to be protecting cis women, who are idealized and treated as personal property and reproductive assets in a patriarchal society. Cis women are the source of future workers (babies) for the ruling class. Cis women are the source of domestic servants (house wives) for the ruling class. They must be "protected" from what transphobes imagine are simply men in drag. Notice how transphobes are always advocating for forcing trans women to compete with cis men to "protect" cis women, but are never advocating for forcing trans men to compete with cis women to "protect" cis men. It's an entirely lopsided ideology fixated on cis women as property as an ideological facade for discriminating against trans people. They won't even advocate a half measure like creating separate leagues in sports for cis and trans the same way it's already separated between men and women, adult and child, abled and differently-abled, professional and casual. Because to do so might incidentally grant more legitimacy to trans identities by admitting them to be categories, and that's the last thing they want to do. They want to ignore, bury, and discriminate against trans people without acknowledging them, or even resolving the contradictions of their own beliefs. Same goes for nonbinary, intersex, etc.