By default, "Admin" role is created for an application. You can define new roles other than the provided roles.
You can delete the default roles as per your requirements. But at least one role needs to be created. This is to ensure that you can access the application.
The cloned applications are assigned with the same set of custom roles, scopes and core roles are inherited from the previous version. For more information on the conditions for creating a custom role, see Developer documentation.
All API (third party APIs and Provisioned APIs) applications can be accessible to standard, Insights Hub Monitor plugin and mobile applications only when third party API roles are provided.