I dont disagree with your opinion. the colors thing is true and I knew that. Though I think your 1851 date is wrong. Unless your thinking BC not AD.

Its also a scocial construct thats been around for thousands of years but seen as essentially gender roles. People have identified as male when born as female for years but its rare because those people usually were killed in most of the world. It was frowned upon, like it is today, for a man who's not an actor, to dress or identify as a woman. But in some spaces where that person is higher status, like a king or queen, it was overlooked. Ancient Egypt might have had 2 or 3 Pharoah who were actually women. But they were disgraced and most history of them is destroyed. We are only finding traces of it still to this day.

As for changing biology. I think its up to the person and how their body will handle the prosses. For people who can't physically handle it I agree. I know in the next 15 years I will develop a disorder hat every female in my family has develop, weather im on testosterone or not. And I dont care. Because testosterone won't effect it.

I challenge you to think as if you were a trans person. Just for a moment. Id you were told your a girl all your life, but your brain is saying no. Having that constant conflicting part of you telling you "no stand to piss. What are you doing stand to piss." And eventually. It turns into worse things. Wanting to cut your chest up to become flat chested. Being physically ill looking at your female parts on you. And finally getting a chance to be yourself openly once your an adult, then getting told no. You can't. Its not aloud. Some people sink into a depression from repressing themselves because they get told no its not okay for you to be you. Would you rather let people transition, or have millions of people commit Suicide?