I jumped directly into SwiftUI for a few macOS apps I published, and the weird performance issues / UI lag / Compose complexity for even simplistic apps were hard to navigate, even after a year.
Yet rewriting components in AppKit/UIKit feels regressive since even Apple's docs migrated to SwiftUI, but sometimes that was the right answer to regain some control over what was going on.
Though some of that was limited to macOS which seems to get a lot less attention from Apple than iOS, or because you're naturally building more complex layouts on macOS. But it always makes me appreciate how much better the kit is for building web frontends.
Most of the layouts I've built on macOS are actually simpler than their iOS counterparts because the mode of interaction is so different. Getting data onto the screen in a somewhat natural way is usually less of a contorted process because one doesn't need to deal with a software keyboard, a narrow viewport, lots of scrolling, etc.
The problem with SwiftUI on macOS in my opinion is that it's just not well-suited to the types of layouts common on desktop and especially macOS. It's best at uniform grids and lists which is more of a mobile thing. On macOS you want things like visually balanced whitespace, optical centering of labels+controls in forms, etc which are often rather arbitrary and exactly the thing that SwiftUI is worst at.
Yet rewriting components in AppKit/UIKit feels regressive since even Apple's docs migrated to SwiftUI, but sometimes that was the right answer to regain some control over what was going on.
Though some of that was limited to macOS which seems to get a lot less attention from Apple than iOS, or because you're naturally building more complex layouts on macOS. But it always makes me appreciate how much better the kit is for building web frontends.