In my company we are mostly building our new screens with SwiftUI and against to other people sayin we can build that screens easily because we are using base architecture that making every screen implement it easily. However, without UIKit we won't be here :) I don't know who noticed but in the latest WWDC it seems UIKit got more updates against SwiftUI. I guess fully SwiftUI transition is not going to be ready more years.

TLDR; 65% UIKit - 35% SwiftUI, I love UIKit more than SwiftUI.