Balkan Sworn Virgins
en.wikipedia.org
en.wikipedia.org
We have worldwide written-history spanning evidence of gender variance.
Like, we've got CUNEIFORM tablets dating back to around 2500 BCE documenting assigned male at birth priests wearing feminine clothing speaking the language of women (as ancient Sumer had different languages for the genders as many ancient cultures had)
In her poem The Exaltation of Inanna (written ~2300BCE), Enheduanna describes how her goddess transforms people:
"To turn a man into a woman and a woman into a man are yours, Inanna."
Hold on, I'm on a role:
In Egypt: Middle Kingdom pottery fragments (Execration texts) list three genders: tai (male), shet (female), and sekhet. The sekhet are generally interpreted by historians as individuals who did not fit biological or social male categories.
In iron age Europe: Enarei were Scythian shamans who were assigned male at birth but lived, dressed, worked, and spoke as women, utilizing an automated spiritual status.
Ancient Rome (c. 218–222 CE): Emperor Elagabalus, A Roman Emperor who defied Roman gender norms by wearing makeup, adopting female titles (such as calling herself a queen), and asking physicians to perform a primitive gender-affirmation surgery.
South Asia: The Hijra,mentioned in ancient texts like the Kama Sutra (c. 200 CE), Hijras are recognized as a third gender in the Indian subcontinent, with a continuous historical lineage stretching back thousands of years.
As far as history is concerned, we have always existed, and it's not our fault that you (who claim it's all so new) are uncultured swine.
Fun fact, I did a cursory look on Wikipedia to remind myself, and it looks like it came about in the exact same year as chemotherapy. Which I find a rather amusing coincidence, considering one of the two is definitely well-accepted --- and yet, very damaging with its side-effects (though alas, very necessary ... cancer sucks).
(small nitpick, because my brain just won't let it slide: it's "I'm on a roll", not "role")
On HRT, you're right in a modern western perspective (and the specific isolation of androgenic/estrogenic compounds of course), but the practice itself is nearly as ancient as gender variance itself.
The feminizing effects of orchiectomy is well documented in ancient cultures. We've got the Han Dynasty distilling mare urine in 200BCE. Egyptian, Greek, and Chinese medicine using licorice root, spearmint and peppermint used across the Mediterranean and Middle Eastern cultures, Pueraria Mirifica (White Kwao Krua) native to the communities of Northern Thailand, and Agua Je (The Curvy Fruit) in Amazonian indigenous traditions.
Surgery is the same story given the existence of eunuchs and that Elagabulus sought surgical relief from his physicians. (^.^)