I appreciate the conversation as well, but the belief that this should be the norm is a cultural construct that has little support in actual biological science -as I've already quoted to you about. This belief is also used even today as a way to shame and discriminate because such people are "wrong" because they are not "the norm." As I said to you in my example of left-handedness, being right-handed was the norm until very recently because being a lefty was punished (they used to smack kids hands with rulers for trying to use their left). When it stopped being the only acceptable thing to be, the world didn't actually change in any meaningful way. The same would be true of letting the natural number of gay/trans people to just be themselves. The world wouldn't actually change for you - although it would change for the better for those who are now hated on for being who they actually are.
And, gay people can still have children. They do it all the time - sometimes through artificial insemmination, adoption, or the old fashioned way even. Besides, the world is already vastly over-populated. Why do we care if not every single human decides to reproduce? That's not the main function of being human. Plenty of people are not able to reproduce for other reasons or choose not to and the world goes on just fine.
Of course we don't want people to experience gender dysphoria, but telling them there is a possibility that they aren't necessarily the gender that their plumbing suggests isn't what's causing that. To say that it's not wrong or even necessarily unusual to have gender dysphoria doesn't mean that we want people to have it or that you are not normal if you don't have it. C'mon, that's just verbal gymnastics right there.
The fact of the matter is, letting impressionable children know that their plumbing is not the only arbiter of their sex is a service - because as I've already demonstrated to you with quotes from Scientific American, it's not. Intersex births are about 1.7% of the population (about the same as red hair). Deciding that a person’s genitals alone determine their sex is too simplistic to be accurate.
According to the Intersex Society of North America, the total number of people whose bodies differ from standard male or female is one in 100 births. About one in every 1500 babies requires a sex differentiation specialist to be brought in to make a determination, but subtler forms of sex anatomy variation that are hormonal or chromosomal may not become apparent until later in life. In other words, a person with a penis isn’t necessarily a man because they may also have ovaries, a vagina, or a scrotum that is empty and resembles labia. Someone born with a vagina may also have internal testes. They may have chromosomes or hormonal levels that are not in alignment with their physiology.
Whether gender identity is acceptable in the US has nothing at all to do with whether it's a reasonable construct. People tend to cling to what they are used to, particularly around something as deeply culturally ingrained as a gender binary, but that being said, nearly half of American adults believe that US forms should offer more than just two options - which indicates that a lot more people than you think are more than fine with the idea of gender identity.
As of now, both the Federal government and at least 15 states offer a third option on forms.
https://www.pewresearch.org/fact-tank/2019/12/18/gender-options-on-forms-or-online-profiles/
Most younger people accept this as a given so eventually it will become a lot more acceptable.
"Younger adults are more likely than their older counterparts to support including third gender options on forms or online profiles. Roughly half of Americans ages 18 to 29 (53%) say that forms should include other gender options, compared with 43% of those ages 30 to 49, 37% of those 50 to 64 and 35% of those 65 and older."
Telling children that who they are is normal and fine, no matter whether it conforms to heteronormative/binary constructs is a smart and compassionate thing to do. Because children who are not taught that frequently go on to kill themselves. Telling them it's OK to be themselves does not indoctrinate them away from being straight; it simply affirms people who aren't straight or who aren't binary. And that doesn't impact other people in any meaningful way. At least that's the way that I see it.