Sincerely. I don’t really know what it means, or the purpose in asking it? Well it seems the purpose in asking it is to try to prove your point that being trans is just make-believe ?
But logically, what is the question?
Do I believe that some people are trans? Yes.
Do I think that sex is a simple, unitary, binary? - no, it evidently isn’t, hence the scandal regarding this boxer. Although there is a powerful reproductive binary that underwrites sex development, sex is complex process of development with multiple components, with variations and diversity that is produced at each stage. Many of these variations have only become visible in fairly recent history with the invention of complex medical technologies ; it is very possible that there is far more yet to be discovered about the complex biology of sex development.
Do I believe that trans people, and people with DSDs (and cisgender and sex- typical people!) can take hormonal therapies that can alter their secondary sex characteristics ? yes.
Can people also have chest and “bottom” surgeries that alter the external structure of their anatomy? Yes. Can people have surgeries that alter their internal reproductive structures? Yes.
Can you legally change your sex? Well that depends on the country, but in the UK you can. Can you socially change your sex? Of course.
Does this answer your question?