Demonstrates a weird bug with SwiftUI where a Section with a `isEnabled` false will allow swipe-to-delete, but not manual deletion where it should prevent both.

section-delete-bug.swift

import SwiftUI

struct ItemView: View {
    @ObservedObject var collection: ItemCollection
    @ObservedObject var item: Item

    var body: some View {
        HStack(alignment: .firstTextBaseline) {
            Text("Item: ")
            Text(item.value)
        }.contextMenu(menuItems: {
            Button(action: {
                self.collection.deleteItem(self.item)
            }) {
                Text("Delete")
                Image(systemName: "trash")
            }
        })
    }
}

struct ContentView: View {

    @ObservedObject var collection: ItemCollection

    var body: some View {
        VStack {
            Form {
                ForEach(collection.items) { item in
                    ItemView(collection: self.collection, item: item)
                }
                .onDelete { (indexes) in
                    self.collection.removeItems(at: indexes)
                }

                // This will allow "Swipe to delete" but otherwise ignore the `contextMenu` deletion
                Section {
                    ForEach(collection.items) { item in
                        ItemView(collection: self.collection, item: item)
                    }
                    .onDelete { (indexes) in
                        self.collection.removeItems(at: indexes)
                    }
                }.environment(\.isEnabled, false)
            }

            Form {
                ForEach(collection.items) { item in
                    ItemView(collection: self.collection, item: item)
                }
                .onDelete { (indexes) in
                    self.collection.removeItems(at: indexes)
                }

            }.environment(\.isEnabled, false)
        }

    }
}

// MARK: - Preview

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView(collection: ItemCollection())
    }
}


// MARK: - Data Model

class Item: ObservableObject, Identifiable {
    let id = UUID()
    var value: String { self.id.uuidString }
}

class ItemCollection: ObservableObject {

    @Published var items: [Item] = [ Item(), Item() ]

    func deleteItem(_ item: Item) {
        self.objectWillChange.send()
        self.items = items.filter({$0.id != item.id })
    }

    func removeItems(at offsets: IndexSet) {
        items.remove(atOffsets: offsets)
    }

}