I’m uncertain if deepfake porn should be banned; it’s already difficult to enforce copyright on the internet, because it’ll just get redistributed.
Similarly, it would be impossible to enforce restrictions on deepfake porn; because it can easily be redistributed.
But only because that’s where technology is today. You need many images of the face at many angles, and it is only a face swap of real video that was captured.
Within 50 years it will be possible to create complete fakes from whole cloth. No images, no video as a source. Only a person’s imagination. At that point it is equivalent of cartoons.