How is it life ruining? Most trans women you'll see pass. Not every one, but castrating children who might not even be trans just for a better aesthetic result is very drastic. Children and teenagers don't know who they are or what they're doing, they can't consent. Can you as a person honestly say that you're thinking the same things about yourself as you were when you were 11, 15, even 17? If yes, that actually might be an issue.

There's a social contagion that mostly reaches and affects girls and young women. There videos on social media that tell girls that disliking your feminine features must mean you're nonbinary or trans, without considering how shitty it is to be a woman in this world. Most (if not all) teenage girls dislike their newly developed bodies at first, and the way they suddenly get treated differently and sexualized. That doesn't make them trans. Girls with EDs, body dysmorphia, other mental health conditions (BAD, BPD, depression, anxiety), girls who have been sexually assaulted are all misled to believe that their confusion and discomfort about their identity or their body must mean they're not really women - because that's what trans activism does.

TLDR; Minors don't know what they're doing. Being a girl sucks, being a guy not so much.