An over-simplification, but an evocative one:
- The social sciences are contentious, their predictions questionable.
- And yet social sciences use the scientific method; AI predictions generally don't.
- Hence predictions involving human-level AI should be treated as less certain than any prediction in the social sciences.
It does sound pretty bad if that's the case. My suspicion is that the models are there, just implicit and poor-quality. Maybe trying to explicate, compare and critique them would be worthwhile.