Intersectionality is all about recognising that we as individuals are members of many different groups both by choice and by birth, and that these differences intersect to give different outcomes to others who may be in some of the same groups but not all.
The origin of intersectional feminism was Black feminists and their understanding that ones race changes how one experiences sexism and ones sex changes how one experiences racism. Crucially, both sex and race were recognised.
Isn't it weird therefore that some people's idea of "intersectionality" seemingly demands that there must be recognition of a group of people who share "behaviour, inclinations & experiences" but are different in sex, and yet no recognition of a group of people who share the same sex but are different in "behaviour, inclinations & experiences"?
To use Intersectionality to argue that one of the intersecting groups is simply a subset of the other is to gravely misunderstand intersectionality.
The "sex is only relevant as a subdivision of gender" view only works if one ignores the needs of female people, who face social disadvantages because of their sex regardless of where they may identify on the "behaviour, inclinations & experiences" scale. One might even consider it to be clear mis-whatever-the-name-for-the-half-of-people-who-are-female-might-be-y to recognise the validity of the first group but not the second.
One might think, if it were truly the case as some assert that is no widespread social, legal or cultural recognition of the group of female people as distinct from male, that in itself justifies the emergence of a social change movement for recognition of sex and sex-based rights and protections to exist.
We could call it whatever-the-name-for-the-half-of-people-who-are-female-might-be-ism, perhaps.
Because sex exists, socialisation based on sex exists, discrimination, abuse and exploitation based on sex exist, and women aren't stupid. Every day more of us see through the Genderist neo-sexist wordplay, and the more we are forced into living by it the more the lie becomes clear.