Additionally, everybody IS male or female. There are only two sexes.
This is simply untrue.
Sure, it's true of the overwhelming majority of people; But there are eight billion plus people alive today, and even a fairly small fraction of such a large number can still be a very large number.
There are large numbers of individuals who are not male or female; People who are neither, or both. Exactly who fits into the two categories you insist upon, and who doesn't, depends on exactly how you define those categories, but there's no definition that generates the dichotomy you insist upon without leaving any exceptions.
And the discussion is about the exceptions.
Saying "Exceptions are difficult, therefore I declare that no exceptions exist" doesn't alter the reality that exceptions do exist.
Saying "Exceptions are biologically impossible, and therefore cannot exist" neither alters the reality that exceptions do exist, nor gives your audience any confidence that you have the slightest clue how complicated the biology you are discussing actually is.
Your fundamental premise is clearly and demonstrably wrong; A single individual out of the entire population would be, and is, a complete refutation of your absolutist claim. And of course there are at the very least thousands, probably millions, of such individuals.
When your argument is founded on a premise that is known to be false, it is very foolish indeed to expect it to lead to conclusions that are true, and even more foolish to expect your audience to be swayed by your claims. And that remains the case even if, by some remarkable luck, your conclusions really are true.