The problem with DRF being an external package is that it does thing slightly different than Django itself would do it.
DRF’s validators don’t implement `__eq__`, Serializers doesn’t implement `serializer._meta.fields` on the base class (you have to instantiate the serializer to access anything other than `declared_fields`), lack of async view support, and on and on.
I find DRF grating and would pay anything to have an official Django REST api contrib package.