This is called gender-critical feminism, a predominantly left-liberal movement that left-progressives in the US don’t distinguish from right-wing anti-trans people like Tucker Carlson. In the UK there is a clearer demarcation between being gender-critical and being anti-trans.
It is based on the idea that violence/harassment/oppression of women is rooted in sex (biology), not gender (social roles) and therefore that sex is the more important and meaningful way to define and protect womanhood, and thus that “woman” means “adult human female”, and is not something that can be identified into.
It is based on the idea that violence/harassment/oppression of women is rooted in sex (biology), not gender (social roles) and therefore that sex is the more important and meaningful way to define and protect womanhood, and thus that “woman” means “adult human female”, and is not something that can be identified into.