No because we’d get prion disease like Creutzfeldt-Jakob and others.

Check out prions if you are not hospital fobiac.

Strangely, the question is “How long could the human race survive on only cannibalism?” A pretty specific question.

But the video is titled “Could we survive eating only humans?” Which is a completely different question, because it allows the interpretation that the humans “we” are eating can eat whatever. It brings to mind the humans of Ringworld that had to fill in all of the niches of other animals.