Indeed, it's quite likely that some large portion of humans exhibit some form of gender dysphoria at some point in their lives (though I haven't personally, many people I know have).

What anti-(sex, gender, queer, etc) crusaders like this also miss is that if no one cared at all about these matters, a lot of people might not be forced to choose a gender so dogmatically and permanently, and people's gender and presentation might change at different periods of their lives.

Since the 1980s, John Varley has written a lot of science fiction stories set a future where having a sex change is a minor medical procedure, unlimitedly reversible, that almost everyone does at least a few times, and in most of the stories, this isn't even the focus, just part of the background. It's glorious. (Varley is generally incapable of writing a dull word.)

And as an older person who a lot of people have confided in, I can also say that if the world really didn't care about other people's sex, sexuality and gender, an awful lot of people would come out as asexual. I honestly feel it's harder to be A than gay (and again, I'm not asexual myself) because it is so isolating.

And again, that might change with age and situation - if we were just free to live as we pleased, without a tiny number of Fascists wanting to get their rage on at everyone else's expense.