
Sex is fluid with multiple chromosomes patterns XX XY XXY XYY X0. To imply sex is stagnant and not fluid hurts both transsexual individuals and intersex people. For some people such as transgender gender queer nb etc they just need gender affirming care and some need sex reassignment treatment and gender affirming care such as transgender transsexual and intersex people. Both groups deserve easy access to these treatments. And for many it is an absolute medical necessity to have it.
personally I think we just need more and stronger definitions of things. too many transphobes try to reduce it to “gender = sex and sex = chromosomes” and it works, because different people have different definitions in their heads of gender and sex. But they obviously can’t deny there are changes if we specifically say “gender presentation” or “primary and secondary sexual characteristics”. specificity helps prevent twisting words