It's pretty simple actually: if it's not your body then it is none of your business.
Medicine has a social context as well. This relatively recent idea that someone can become more female or more male through drugs and surgery is one that has repercussions on how we as a society view the two sexes, what constitutes a woman or a man, and what is an acceptable expression of one's masculinity or femininity.
Maybe it's the right idea. But we should all reserve the right to be critical and consider alternatives, for this and any other idea with broad societal implications.
The social context has nothing to do with it, that's just a way to say that if enough people say that you can't do to yourself what you want to that that makes them right, which has historically led to all kinds of wrongs. See also: the right to euthanasia, abortion, being gay and so on and so on. It's always the sanctimonious groups that are hell bent on telling others how to live, but it never was any of their business.
How 'we as society' view this has no bearing on something that is ultimately the domain of a single individual, the person affected.
In the United States this is codified by "The right of the people to be secure in their persons" though of course there is plenty of hairsplitting going on about what that actually means, even though the simplest reading is to take it for what it says.
The implications of this are far reaching (for instance: I'm on the one side against a vaccine mandate because it would infringe on that right, on the other I think that a lot of people have allowed themselves to be pushed towards this on a pretext).
If you naively consider the topic only from a bodily autonomy perspective, then the answer is deceptively simple: get the blades out and start slicing. But this ignores the wider medical ethics concerns over whether it's the right thing to do for the patient, if the surgeon is causing harm by doing so, if gratifying the patient's short-term desires genuinely helps them in the long-term over their entire life, if it's reasonable to expect a surgeon to perform such a procedure and how they may feel in the aftermath, if there are any other interventions that would be more effective. And societal questions over whether it's ethical to deliberately add new members to a population who already find it difficult to find the support they need, how this will affect others who may now be situational obliged to assist with this person's new disability, and so on.
It makes no sense to focus solely on the individual and ignore the wider context, when there are so many other factors to consider.
So this strawman won't stand.
So before you go off on a tangent about what is and is not accepted practice and which things doctors are required to do and which things they abstain from on ethical grounds I will have to bow out because we are at the limits of my knowledge on the subject and that's not for want of reading material. Let me close with: I know where the line lies in simple cases, but if you start dragging in things that I have not spent enough time on/read about/have knowledge about then I simply will not be able to hold that conversation. If you have this knowledge then more power to you, but so far you have not convinced me of it and you come across as an ideologue.
The only joy I found in life before I transitioned fully was in doing drugs and hooking up with guys. I could have maybe started a career and settled down with a man while living as a gay man but I doubt it. My misery was all consuming. My goodness, when I was 5 or 6 I remember bargaining with God to make me a girl and vowing to hold my breath until he would. I passed out many nights doing that in bed when I was alone with my thoughts and my sadness about not being a girl hit the hardest.
As a teenager I could barely function and nearly died from an eating disorder. I hated every masculine thing about my body and with testosterone pumping through me the only thing I could do to feel less masculine was starve myself, to try to be smaller.... In short I wasn't functional and I was physically withering away to the point where pneumonia nearly killed me because my body was so weak.
After I transitioned I stopped living in survival mode and started building an actual life.... I also gained a few pounds and got fit instead of being a shambling skeleton. I doubt my story is unique among gender dysphorics.
So whatever. You can debate the ethics of whether or not society was better off with me being a starving depressed twink versus a trans woman I guess but if you think it's bad for society that I was able to look how I want and start a family and feel happy I think you've got weird ideas about how the world works.
The Hijra community (Indian trans/non-binary) has been around for thousands of years, and surgical castration has been one traditional way for them to achieve their identity during that period. It's not relatively recent.
https://rpl.hds.harvard.edu/religion-context/case-studies/ge...
In any event, I think in a free society we must start with the premise that all things are permitted and only with valid reason restrict that freedom. There are many valid reasons, but merely being critical of someone else's means of existence is not what I would regard as sufficient reason to restrict their personal freedom. At a minimum, potentially cognizable harm should be shown. And to be clear, I don't think there's any potentially cognizable harm to be found in someone conforming to their own gender identity.
Many trans people that join the hijra community leave it due to the abuse. The ex-hijra community is one of trans women that has been around for roughly as long as the hijra community has been.
Here's a project from former members of the hijra community that left because of the abuse they faced in it: https://aravaniartproject.com
In any case, trans people have been around for as long as people have been around.
The western idea of transness is better (more freedom, less suffering) so of course it is seeing adoption worldwide. I'm the exact opposite of a cultural relativist. I think it is morally good for the best cultural ideas to win.
In any case it still doesn't change the fact that something resembling trans people have been around in every single culture for a very long time. It is because transness is universal, a part of the human condition.