As a developer, the experience is so much better on Android for me. And I oppose the walled garden on a ideological level.
But I have to admit some of the features are compelling. Some of them aren't even really Apple's doing, such as Genshin Impact supporting wireless controllers on IOS14+, but not Android at all. Others are built in, such as the lidar scanning.
They haven't yet tempted me over, though, because phones are incredibly expensive and even if I weren't opposed to the walled garden, I'm pretty invested in the Android ecosystem now.
At some point I plan to borrow someone's iPhone and try Genshin on it, and if that works well... Well, I might just switch anyhow. Or maybe I get sick of that game before that. ;)
The Bobiverse series eventually features some aliens. I don't think that's a spoiler at all... But they aren't space-faring, so I dunno if that counts for what you're looking for.