Elliott Page is not a teenager. He’s a decade past full brain development. You’re infantalizing him.
We don’t seem to have the same problem with allowing young people, even teenagers get breast implants or nose jobs, or chiseled jaws. Those are happening with increasing frequency. So why is it never a concern that an 18 year old who wants big boob implants may decide in 10 years that she’s a masculine lesbian and would feel better about herself with no breasts or nothing bigger than A cup breasts?
Your argument isn’t about body modification. You’re upset because some of the people getting it aren’t getting it to your idea of gender performance. They’re getting it to theirs. So you’re sticking your nose in where it doesn’t belong and trouncing all over someone else’s right to do what they want with their own body.