I've seen a lot of takes talk about the history of Destiel, and express shock at the anime girls they don't know about. Many people have already covered why they love Sulemio, but I want to point out I don't think Sulemio winning is all that surprising. But people are surprised because they've been limited to tumblr.
First, people arguing that Destiel raised this website are right. But that's not how people vote. People are voting for the ship they love, history or otherwise. At the end of the day it is a fan poll. Have fun.
Second, is that the poll has long escaped tumblr containment. I only heard about this poll cause someone linked it on discord and twitter. Again, don't think that's wrong. Internet is an ecosystem. People are free to do as they please. Whether that's a fan heavily stanning for her followers (like a certain demon girl) on tumblr, or sharing the poll elsewhere it's fine. And while Destiel may long reign way on tumblr, Sulemio and G-witch have extensive pull on other sites. Namely twitter, where the G-witch tag was the 3rd trending keyword in japan. Not just anime or tv/media, 3rd trending over all.
Sulemio was also the most popular ship on pixiv of 2023 and 9th most popular yuri ship over all (all from one user so results may vary). They topped 3rd at the last two comikets for shipping (which if you know the history of comiket recently, is basically first).
So they are popular in japan and on other websites, so what? Well that kind of leads to the corollary of the "Destial is king" is just limited to tumblr--it's also limited to just basically American media and what's popular in America. Not only has this poll breached tumblr, it has managed to break American fandom, and notably language barriers. How much? I don't know, but I have seen nonenglish speakers in retweets on sulemio fans posting about this.
And more than just "Sulemio is really popular", Sulemio is really popular because *Gundam itself is nightmarishly popular in some countries*. Japan itself used to have a full mechanized Gundam display that got taken down this past spring. They still have another life sized Gundam Statue, and Hong Kong has their own. Gundam is almost single handily responsible for modern otaku culture in japan. A BL ship from the original anime existed before BL shipping was a thing in japan.
The original set of Gundam media, made 1979-1989, is one of those anime that once you seen it you see the references everywhere. Pokemon? That's got Gundam references. Evangelion, Utena? Those pull from Gundam. Kirby? Meta-knight is a whole ass Gundam reference, hell his game in Super Star is a Gundam reference in of itself to Char's Counter Attack. Once you know Gundam, you'll never see a Blonde Haired Red anime rivals again. All you'll see is that fucking bastard man. If you consider yourself an anime fan, I genuinely recommend at least familiarizing yourself with First Gundam for the sake of contextualizing nearly every anime you've seen.
And G-Witch sits in the legacy of Gundam. It probably won't have the same cultural legacy, but G-witch did make Gundam popular again in japan (for better or for worse), to the point one of the songs of the show got sang as part of a talent/parody program.
What is this to say? Gundam is basically Star Wars levels for pop culture impact in certain countries. Last summer, G-Witch trended with nearly a million tweets for it's finale, the day twitter fucking broke. Then Bandai Namco tried to water down Sulemio saying "their marriage was open to interpretation". What happened was the international g-witch fandom gave a verbal beat down to Bandai Namco. And they arguably won. So I don't think its that surprising a very recent, and very popular, ship is winning.
So many Sulemios are calling,
beyond the tumblr.