Congrats, you came in here with a pointless hot take using arguments commonly weaponized against marginalized groups, and succeeded in upsetting that group and their allies. *slow clap*

First of all:

0.016*330,000,000 = 5.28 million individuals.

That's a huge chunk of the population of the US. Your odds of brain cancer or being hit by lightning are also small, but we don't get all bitchy edgelord about it. We accept that in huge populations, outliers are fairly common.

Humans aren't coins, and even "edge cases" need to be accounted for in medicine/law. Whether it's "bInAry" or not doesn't matter. These people exist, en masse.

Second of all:

AFAIK almost no one is arguing that human biological sex isn't overwhelmingly binary. If aliens came down and tried to mix our cells in a lab, they'd have two "basic models" to work with. There't no real disagreement.

In fact, the discusions about "non-binary" issues center around gender and gender identity, which biology isn't nearly as closely tied to. Even the responses you're getting here support that, even if they're not using those words. They're all talking about presentation, etc.

Bodies and minds can develop in countless variations. Even if a person is born bog-standard XY, they could develop a feminine appearance and identify, and also vice-versa. Hormones and society are weird.