There indeed are many people pushing the idea that sex isn't binary using things like Disorders of Sexual Development (intersex), other species that can change sex like clownfish (pretending this says something about humans), and also creating confusion between sex and gender and conflating them (such as how your sex is listed on ID, but people claim a gender, such as the opposite sex or non-binary, and have that gender listed as their sex).
I should have been clearer, sex is generally binary there are obviously rare exceptions like chromosomal abnormalities.
Who's making these arguments? A quick Google scholar was not fruitful, do you have any sources or is this a fringe minority?
> such as how your sex is listed on ID
This presupposes that sex be listed on ID rather than gender. I don't follow this in the news so I'm not sure what the arguments are but at face value using the IOM definition from 2001 ("how that person is responded to by social institutions on the basis of the individual’s gender presentation.") gender seems like the more appropriate choice for identification.
