Sex isn't as simple as male/female xy/xx either. You've got genotype vs phenotype vs dominant hormones where something like chronic androgen insensitivity syndrome where you have y chromosome but are AFAB. Or intersex people who don't conform to the man=penis=xy that is typical. Or just trans people on hormones for long enough that your hormones levels are at that of a cis person. It's not binary.
Sex isn't as simple as male/female xy/xx either. You've got genotype vs phenotype vs dominant hormones where something like chronic androgen insensitivity syndrome where you have y chromosome but are AFAB. Or intersex people who don't conform to the man=penis=xy that is typical. Or just trans people on hormones for long enough that your hormones levels are at that of a cis person. It's not binary.