I have two questions concerning gender identity. Does third gender (female with male genitalia) or (male with female genitalia ) occur naturally? And why some transsexual people don't want to have "bottom" surgery?
gender and sex are two completely separate things.... and i think it is problematic to look for a single answer in any one thing to explain why some people do not want bottom surgery. there are an infinite number of possible reasons why one may not want surgery, whether female, male or non-binary.
If you're talking about intersex people then yes, it does occur naturally, but they're not a "third gender." There's a spectrum of intersex people, but only an individual person can define their gender identity.