Since Swift got ABI “stable” stamp the runtime and standard libraries is shipped with the OS, reducing the overhead by ~50 mb.
Where do you see 3mb? I see "4.3 MB" on the App Store page but still that's impressive.
When an app is uploaded to the app store, it is compiled for every different device separately. You likely have a higher resolution phone/device than the OP, so there's more image data on your version
Exactly. Older iPhone 6S here, showing 2.1 MB
I've noticed a differing pattern in our app: usually the newer devices (11 Pro Max) have a smaller foot print than older devices (iPhone 7 Plus) [1]