The Declarative Revolution
SwiftUI is declarative (State -> View). UIKit is imperative (Controller -> View). Declarative is faster to write and less bug-prone for state management.
SwiftUI Maturity
By 2026, SwiftUI covers 95% of use cases. Navigation is fixed. Performance is solid. It is the default for Apple platforms (watchOS, visionOS).
When UIKit is Still King
Complex custom navigations, heavy text rendering optimization, or maintaining massive legacy codebases. UIKit isn't going away, it powers SwiftUI under the hood.
Interoperability
UIHostingController and UIViewRepresentable make mixing them easy. You don't have to choose 100%. Use the best tool for the specific screen.
Developer Velocity
SwiftUI is 3x faster to write. Live Previews (when they work) speed up iteration loops massively.
Job Market Demands
Startups want SwiftUI. Big Tech needs both (maintenance vs new features). Knowing UIKit basics is still a "Senior" requirement.
The Verdict
Learn SwiftUI first. Pick up UIKit patterns as you need to bridge gaps. The future is indisputably declarative.