Why would biology scare those who are trans? If you look at biology it shows grey matter in your brain does impact your gender identity.
Plus, if gender was just chromosomes, then why do cis people use pronouns, why do guys get offended when called a girl and vise versa? Why would women get so much cosmetic surgery to appear more feminine.
It's not a social construct, in fact it is biological and psychological. But why is being trans so wrong?