If I had to implement a compiler or a database, I'd definitely pick a language with a powerful and strict type system like Swift. It's fantastic when the compiler can prevent large classes of errors. I mean, even trivial concepts like an Array<Point2D> are frustrating to express in Objective-C (wrapping C structs with NSValue? Ugh).

But that's not how iOS development works in my experience (YMMV). Most of the logic lives either in the backend or in C/C++ libraries, and Objective-C is just the glue between that and UI frameworks. When this glue layer gets complicated, it's usually because of animations, AutoLayout, UIKit bugs, or workarounds around performance issues. But all of these are issues with the frameworks, not with the programming language.

Objective-C is effectively a domain-specific language for Cocoa. Swift aims to be the next big general-purpose programming language, but it's still only being used for Cocoa. I think this is fundamentally the wrong direction.