Sex mattered in sport and women only sport was accepted as perfectly sensible until male people wanted it.
The endless splitting of hairs on how much it affects female athletes negatively is merely establishing some temporary boundaries on just how much grace they will be permitted in the providing of their sports to male entrants.
The bottom line is quite simply: did female athletes go through all their training, their efforts, their struggles, to provide emotional care and inclusive support to a male athlete?
Look at your daughter. Are you prepared to tell her that by accident of being born female, her ambitions, her dreams, her feelings, her needs, must always come second to her primary purpose of serving male interests?
And then explain too that no, sex isn't supposed to exist or matter, and yet hers does. This is wholly sex based thinking underpinning all of this, complete with the same hierarchy. There is no respect for female born people anywhere in it.