The QmlElement decorator returns an object type instead of returning the original type. Because of that, the IDE's can't handle a type decorated with @QmlElement correctly:

• creating a decorated object is shown as an error
• object's methods or properties are not shown by auto-complete

Here is a small code sample:

@QmlElement
@QmlUncreatable("Can only be created in python.")  # type: ignore
class Project(QObject):
   pass

proj = Project()