Without a meaningful definition of 'woman', women's rights can't exist.
I don't understand why this is so difficult to grasp.
It's ludicrous that we are having to fight for the definition of 'woman'. I entirely agree that we should not have to fight for this: there are other things we need to fight for.
However, the definition underpins everything else. How on earth do you fight for the rights of 'not males'?
So yes: the questions 'what is a woman' and 'what characteristics are shared by women and transwomen that are not also shared by men and transmen' are critical to working out who women are as a class, and what rights and protections are specific to that class.
I see a lot of people on this board agitating about our seeming-obsession with definitions. It is telling, however, that they tend to leave the board rather than answer any questions.