Ok I'm not Raph but, FWIW, my 3d sculpting app is written using SwiftUI (https://sculptura.app), which is not a view around a database (in fact it was previously UIKit... SwiftUI is so much better). I recently implemented a piano-roll editor in SwiftUI: https://github.com/AudioKit/AudioKitUI/tree/main/Sources/Aud.... I have little doubt a DAW, at least, could be implemented in SwiftUI easier than with UIKit or AppKit.