Cascade delete on recursive relationship

I have a recursive resource related to itself.

I can destroy a record with reference :parent, index?: true, on_delete: :delete and all nested children are deleted by PostgreSQL.

I later found cascade_destroy. What would it do differently? Would it run the destroy action for all nested children records? Is it useful for soft destroys?

    destroy :destroy do
      primary? true
      change cascade_destroy(:children, action: :destroy)
    end

I tried removing on_delete: :delete and using it, but it didn’t work?

Do I need on_delete: :delete or deferrable: true to use cascade_destroy?

{:error,
 %Ash.Error.Invalid{
   errors: [
     %Ash.Error.Changes.InvalidAttribute{
       field: :id,
       message: "would leave records behind",
       private_vars: [
         constraint: "entities_parent_id_fkey",
         constraint_type: :foreign_key,
         detail: "Key (id)=(02df79f3-8b30-4288-bb50-ac446cc97f41) is still referenced from table \"entities\"."
       ],
       value: nil,
       splode: Ash.Error,
       bread_crumbs: [],
       vars: [],
       path: [],
       stacktrace: #Splode.Stacktrace<>,
       class: :invalid
     }
   ]
 }}