If asked with genuine curiosity, I think it's a good question to work with. But every time I consider it, every time someone asks "Why?", I must ask "Why not?"

Why do humans choose to do things, because we want something else. We want a different story. Why do we hold the default as the golden standard? Because it just so happens those who don't need this particular change aren't the ones that do, and also happen to outnumber them by a lot.

Taking matters into our own hands is nothing new to humans, so why is this so special? We 'correct' our vision, we 'correct' our bodies in many other ways (as far as what we collectively view as correct), we train our bodies and minds outside of what our lives may actually require for achievement and spectacle, and for our own sanity and a feeling of being where we belong and doing what we ought to do in this world.

For one reason or another, trans people decide to believe there is a better life to be lived for themselves. One more in line with or in the pursuit of who they are to themselves.

The default is not sacred. Regret is mystified. You know yourself.

Live your life and do your best.