> And the slightly different sizes of iPhones are not really that problematic with something like autolayout

It can be problematic regardless of the technical solution, though generally I have to agree with the loudest voices on this thread: SwiftUI is a load of rubbish, UIKit and autolayout (and Interface Builder) was better.

Regarding problems with all layouts: I've got a 2022 model iPhone SE, so smallest screen, and every so often run into an app which just doesn't handle the screensize right. I've seen this happen as a developer with both UIKit and SwiftUI, it's just the type of bug you end up seeing is different.