The loading bar that I implemented in our app at work is real. It only advances when it has done something, and it advanced that % of the total when it has done it.
It gets away with that because unlikely other bars mentioned here, what's it's doing is a lot of little things that all take about the same time, and so it's actually a pretty decent approximation of how much is done.
So there's at least one that isn't fake. ;)
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. ;)