Sex changes/gender transitions is an actual boring health problem. The inability to assume the correct gender for a trans person often leads to social rejection, violence, poverty, prostitution, murder, and suicide.
If you feel like a man but you don't look like a man, why could that cause any identity problems? It must mean your body is actually part of your identity, so changing it changes who you are
That’s contrary to most of human history, where we specifically try not to take what we’re dealt.
It’s useful to ask yourself: why should vaccines be "allowed" (or "accepted" or "they’re good") but body change shouldn’t be? They’re both as artificial as a Twinkie.
Trans is a much discussed variant that is hard to have a normal talk about, but there are many more variants, for instance women hating their breast & wanting to remove them, I think most people here would agree that intensive psychological treatment are preferable to actually removing healthy body parts. But in the end an adult can do what they want.
On the other hand, a bodily alteration is much more predictable, and, importantly, I'd still be me. I wouldn't become some other person.
This me has an instinct for self-preservation. Thus, if both options were available, I would absolutely choose transition over erasure.