I totally support anyone doing anything they need to be happy, and especially to banish dysphoria.
But I have trouble believing the majority of trans women need FFS. Maybe I just have an exceptionally fortunate group of friends? Out of 30 or so, only one is still being misgendered more than a year after starting HRT... and she hasn't changed her voice at all, and only gets "sir" after she speaks. I haven't had a problem since about six months after HRT.