The most practical consequence of "trans women are not women" is that it forces institutions to police womanhood, and that policing always lands hardest on anyone who doesn't fit a narrow script. Think of a trans woman using a domestic violence shelter or a women's restroom: excluding her doesn't make those spaces safer, it just moves risk onto her. My opponent may have real concerns about sex-based privacy and fairness, and those deserve practical answers. But the better third way is to set behavior rules for shared spaces and fair eligibility rules for sport, not to deny a whole group's legal and social identity.