Before I offend everyone let me clarify that I mean no harm, I'm just ignorant. I never figured out what gender identity is since mostly only rainbow people talk about it and I always identified as myself and not as a gender. The first time I ever heard the concept of gender identity was back in 2017 and never managed to figure it out, too complex for my reptilian brain. I'm 23 and I only know about gender identity from YouTube, people in real life, at least in all the countries I lived so far (Italy, Greece, Romania and Hungary) they never mention things like gender identity.
So maybe the premise of this entire question is completely wrong due to my ignorance but googling around and doing some researching... I just get more confused than before.
So, in a world where males and females can do whatever the hell they want in society regardless of gender.
Gender is not a role but just a sex, gender means only what kind of junk you got in your pants not your role in society and how you are supposed to act, talk and think.
In this world people can identify each other easily from smell, you don't need to do anything to make your gender public, everyone will know just from smelling you at a distance.
So would people with gender identities still exist in such a world? Or would they instead develop a smell identity maybe even to the point of having transhodorous people masking their scent with perfumes?
As far as I understand it gender roles where adopted for different things but one of them is that even if the bone structures of men and women can differ, at the end they look really similar. Specifically when you have many populations of people without beards, teens, juvenile adults... And males with physical feminine features as well as females with masculine features.
What I'm referring too is more like a gender etiquette... Like boys cut their hair and girls wear skirts, side things society use so males who are not particularly masculine and females which don't look particularly feminine do not have to scream and announce their gender every time they meet someone new, everyone can guess everyone else's gender just by their mannerism and clothing.
Now, removing any gender role and gender ediquette, every time you see a woman who's not so curvy and looks like a feminine boy, you don't have to ask her gender, you just feel the scent.
Missgendering people can easily happen during mass gatherings where a lot of unknown people gather for festivities, rituals and political things.