Rebecca R-C says many insightful things at Am I cisgender? | Slave of the Passions. This is from the comments: "The glaringly obvious and ironic thing about people calling themselves “non-binary” is that it creates a false binary between people who accept the gender binary and conform to gender norms, and those who don’t. Everybody is non-binary."
If I ever find myself in another discussion with a gender theorist who says I'm a straight man, I'll reply, "Die in a fire, truscum! I am an AMAB male-presenting lesbian." Because, frankly, that's as useful a description of my gender as any.