Hmm, thinking about this makes me realize how much it depends on which corner of the internet you're in. Over on AO3, the top fandom by far is still 'My Hero Academia', and Kacchako (Bakugo/Ochaco) has absolutely skyrocketed this year. I'm not even a huge shipper for it, but you can't scroll the tag without tripping over new fics. Steve Harrington/Eddie Munson from 'Stranger Things' also has a permanent chokehold on the site—it feels like the natural successor to all those Supernatural ships that used to dominate. The staying power is kind of wild.
What's interesting is watching the slow rise of something like Zenitsu/Nezuko from 'Demon Slayer'; it's not top ten yet, but the tag grows steadily, which usually means it's bubbling under with younger readers. And you can't ignore the old guard either—Dramione (Draco/Hermione) just won't die, and I'm honestly not mad about it. It's less about what's 'new' and more about what old ship has new fuel, like a video game remaster or a movie sequel dropping.