I think it’s gained traction for two reasons.
1. Because it’s a men’s rights movement. Trans identified females are swept along with it, but they’re collateral damage. This movement has always been about men and not women.
2. Because it plays into the heart of liberal people who want nothing more than to feel like they’re the nicest, kindest, most enlightened, tolerant, broad-minded people in society. It’s so easy. All you need to do is pointlessly add your pronouns on work emails/social media, tweak your language a bit, and grandstand on social media about how unisex toilets “wouldn’t bother me”. Congratulations. You are such a good person