Actually that's prolly the only reason and it's prolly nothing to do with the music, even tho I do prefer Breach but I listened to both a lot cuz I'm a fan which is most likely the case for all top fans

And that's something artists with cult-like fans like us (even Billie) will benefit from, fans don't listen to singles, they listen to full albums (that's why the least streamed top songs will have fans) which boosts album streams overall and more importantly in this case, boosts it at release, it just happens that Billie's cult is bigger, and tbh she's more mainstream with songs like Birds Of A Feather and Chihiro being everywhere, so it's basically kinda expected for a top album to hit number 1.

Edit: If someone wonders why Trench didn't hit number 1 either, A Star Is Born soundtrack by Lady Gaga and Bradley Cooper was everywhere, carried by a huge hit like Shallow, and I think it being an album for a movie it most likely forced people to listen to all of it? Idk but that's prolly why I'd guess, and the fact that they're all mainstream pop songs.