I think there's likely a mix of all three. There's the age-old teen "rebellion trend", where being a green-haired enby is the new emo/punk, the RGOD element, which is the new anorexia/BDD, and the genuinely gender dysphoric who really do feel a painfully strong incongruence between their sex and their gender, a minority of whom may eventually be helped by an eyes-wide-open, fully informed physical transition. Combine that with the fact that "gender" has also become a sort of twisted facsimile for "personality", we have a culture that sees victimhood as virtue and trauma as a permanent feature rather than a wound to be fixed, and we're exposing children to an unsupervised internet way too young, where they can see all the worst facets of anonymous behaviour along with extreme porn and the "highlight reels" of the unattainable lives and looks of the rich and famous... well. If the adults in the room abdicate their responsibility—which in many cases they have, whether through ignorance, cowardice or confusion—it's a recipe for disaster.
My only solace right now is that when this moment is over—and I do believe that it will be over, partly because it makes absurd claims that cannot stand up to the merest scrutiny and partly because it's already getting a little bit uncool to have an "interesting" gender—I will be able to say that I stood up, that I always cared for the victims of this poisonous ideology even when it was risky to do so, and that I helped in the effort to bring it to an end.