At the WWDC 2019 Keynote, we were introduced to SwiftUI, a new way to make building interfaces even easier and more readable while building apps in Swift. I thought this looked really cool and a lot easier to use in some cases, but could be a pain to implement in older apps. What do you think about it?
Seems Apple saw React success 
I don’t believe Apple intended older apps be rewritten to use SwiftUI. It is intended for new apps and as a means going forward.
Indeed. But the design is interesting, and comes very close to how JSX / React does it.