Since Swift UI is iOS-first, when the apps get ported to MacOS, they bring a lot of mobile-isms: the views and animations are often wrong, the controls are often wrong (like even the Apple's own settings app breaks
a lot of established platform conventions and Apple's own HIGs), integration with system services is often incomplete (like proper keyboard shortcuts, I can't set a shortcut for Conversations->Delete in Messages anymore) etc.
Because of that I've seen people discuss that they have to reach for AppKit and/or ditch SwiftUI and got all in with AppKit, and that is easier to do from Obj-C.