It's A Quote

[GrandizerII]

That isn't science, it's picking criteria that align with their ideology despite the science. Science has no problem with gender, which is why the APA removed gender dysphoria from the DSM-V nearly two decades ago. The whole "Science can't determine... blah, blah, blah, blah" schtick is nothing more than a talking point from the far right. It's no more valid in this instance than it is when the creationists say the same things about fossils or speciation.

Suppose you have two people in a room, and both of them say they are a woman. But one of them is lying -- he's really a man.

What scientific test can you apply to determine which one is lying?

The answer is whatever scientific tests we consider to be valid for determining who is lying.

The same challenge applies to two people claiming they are autistic, or introverts, or lovers of art.

Also, gender is defined so that it need not always align with biological sex, and this is an appropriate working definition due to what has been both observed and reported more than enough times. So it's a fact that gender does not always align with biological sex, just as genitalia does not always align with biological sex, just as chromosomes do not always align with biological sex.