I understand perfectly that gender is 'the roles, expectations, and classifications societies attach to being male or female' - that's central to my gender critical radical lesbian feminism.
That is not, however, how it has been defined by trans rights activists over the years - it has been referred to as an inner belief, a soul, a perception, a manifestation, an expression - many variable and entirely subjective definitions.
That is not a viable basis for legislation, as the current anomalies thrown up by gender recognition legislation around the world is demonstrating: making laws based on something that has so many definitions, and no agreed definition, is proving to be damaging to public perception of the law. The creation of the legal fiction that a person has changed sex when changing sex, as you agree, is totally impossible, makes the law look like an ass.
If transgender people now claim they are not changing sex, they are changing their gender [and that is a change, from 'transwomen are 100% women like any other woman and how dare you suggest otherwise'?], why should the law get involved at all?
Trans people are not the only demographic that reject ' the roles, expectations, and classifications societies attach to being male or female'.
People like me do it every moment of our lives, but 'we don't need no piece of paper from the City Hall keeping us tied and true'
to who we are and how we live our rejection of gender stereotypes.