One possible cause of transgenderism being in vogue is a continuation of the 70s-80s fashionable androgynous models. A new generation of homogenized consumerist classes, similar to the previous one, but to a much larger extent, feels threatened by a sheer disruptive force of masculinity as well as femininity.
And this disruptive, dangerous force is directly related to procreation.
Only something in the middle, some vague creature, removed from the procreative process and with undeterminable sex attributes seems non-threatening, entirely pliable, and could be as subservient in one situation as dominating in another.
True males and females are literally Nazis, following the natural order of things (Ordnung!).