You clearly have no idea what the science on this says.
1. Anthropologists, have determined through 150+ years of observation and study. Modern Gender roles are purely a modern invention. Most Hunter Gather societies ie African Aboriginals, South American Aboriginals, and Australian Aboriginals, traditionally do not have any gender roles until childbirth, women generally spend more time with the children than men. Both males and female hunt, both males and females gather. However in these archaic societies they have gender non-conforming individuals, and they actually have a separate role within the communities. They usually end up as witch-doctors, shaman, or other culturally significant religious people, ie primitive societies gay and trans means they become the priest class.
2. Cutting edge science says, the assumed binaries of gender are false. And more research is needed. There are plenty of case studies, and small number studies that show the assumptions from the past to be false, however there has not yet been a full or comprehensive study on the subject, yet every-time they look closely the data comes up with unexpected results.
ie they recently discovered
Chimera DNA in humans, something that is common in lower mammals, but has never been officially documented until recently. In fact no one ever stopped to think it was possible.
So you stand on old assumptions, and refuse to see that humanity is only just now discovering how complex humans really are.