For ios 16+ use .toolbar(.hidden, for: .navigationBar) to hide navigation bar as .navigationBarHidden has been deprecated. https://developer.apple.com/documentation/swiftui/view/navigationbarhidden(_:)

    NavigationView {
        List {
            Text("Test 1")
            Text("Test 2")
            Text("Test 3")
            Text("Test 4")
            Text("Test 5")
        }
        .toolbar(.hidden, for: .navigationBar)
    }        

NavigationView is also deprecated, use NavigationStack of NavigationSplitView. https://developer.apple.com/documentation/swiftui/navigationlink/init(destination:tag:selection:label:)

        NavigationStack {
            List {
                Text("Test 1")
                Text("Test 2")
                Text("Test 3")
                Text("Test 4")
                Text("Test 5")
            }
            .toolbar(.hidden, for: .navigationBar)
        }