The sport thing is a real issue for TRAs - because its an area which is incredibly difficult to claim that transwomen are women. There are clear differences and they just cannot be denied. Even Emily Bridges claiming that they lowered their testosterone enough to compete and now has no advantage - just talking about the fact they have to artificially alter their body is acknowledging that they are not actually female, not even close.
And the problem is, once you concede that transwomen are not actually women in one aspect of policy, it makes it a hell of a lot harder to claim that they are women in another aspect. And the wheels start coming off.
But anything that is built upon a fundamental lie, which trans ideology is, will eventually start to crumble anyway.