Do you make a habit of collecting eggs and/or sperm from the people you meet for the purpose of determining their biological sex? How many of your friends’ and acquaintances’ gametes have you confirmed?
If this person[1] tells you that they are a man, what level of scrutiny should they be subject to in order to confirm this to your satisfaction? If you do not intend to reproduce with them, to what end is it important that you establish which type of gamete they produce?
If a future surgery allows a woman to produce sperm, is this what will qualify them as a man from your perspective?
Where do hermaphrodites fit into this picture? What about people that produce neither sperm nor ova?
Do you consider a tomato to be a vegetable or a fruit?
Biologically, a tomato is a fruit. This is inarguable fact. If you are a biologist breeding new strains, you will conceptualize a tomato as a fruit. And yet culinarily a tomato is a vegetable. Put a tomato in a fruit salad and people are going to look at you funny. Note that a biologist who eats food can and will consider a tomato both a fruit and a vegetable depending on the context.
If you can understand this, you can understand that someone’s biological sex—primarily relevant to reproduction and healthcare—can differ from their psychological sex (i.e., their gender), which is more relevant to social contexts. Both can be true simultaneously, but unless you’re a doctor caring for a trans person or intending to perform reproductive acts with them, someone’s psychological sex is almost certainly more relevant to your relationship with them than which gamete they happen excrete.
Sex is way more important in social context. If I am looking for sexual relationship I am interested only in females. For other social contexts I don't really care whether someone is male or female or thinks they are someone else. Gender is irrelevant.
What if you produce neither or both from birth? What if surgery changes which of those, if any, you produce?
What if I told you that none of this really matters to me? What if people discriminating against people who want to be one or the other now makes it matter because discrimination increases crime and reduces productivity?
> If a surgery changes their chromosome then they change sex too.
Now you've completely changed your definition in the course of a few minutes, but you still don't want to change your beliefs. Funny how that works. Imagining what your new definition will be, what if you have any of these sex chromosome anomalies, as more than 2 out of every thousand humans do? What if you use gene therapy to change your chromosomes but don't alter your anatomy? https://en.wikipedia.org/wiki/Sex_chromosome_anomalies
> What if I tell you I don't care what sex you are or you think you are.
Then why are you making a big deal of trying to define it for others and supporting those trying to legislate who can believe what?
> If someone believes for example, they are Apache Helicopter, good for them.
Certainly. That's no skin off my back, just like people believing in magical invisible beings and praying to them doesn't affect anybody else. Both groups can believe what they like.
Legislating who gets to identify as what when it's not hurting anybody does make society worse, just like the people who believe in magical invisible beings legislating what everyone else can do based on the voices they hear in their heads also make society worse. That is a problem worth fighting against.
If this person[1] tells you that they are a man, what level of scrutiny should they be subject to in order to confirm this to your satisfaction? If you do not intend to reproduce with them, to what end is it important that you establish which type of gamete they produce?
If a future surgery allows a woman to produce sperm, is this what will qualify them as a man from your perspective?
Where do hermaphrodites fit into this picture? What about people that produce neither sperm nor ova?
[1]: https://trueactivist.com/wp-content/uploads/2017/07/transgen...