Swiftui Guideline: State — Use @StateObject for reference types. Description: ObservableObject owned by view. Do: @StateObject for view-created objects. Don't: @ObservedObject for owned objects. Good Example: @StateObject private var vm = ViewModel(). Bad Example: @ObservedObject var vm = ViewModel(). Severity: High. Docs: https://developer.apple.com/documentation/swiftui/stateobject.