No one's saying not to have algorithms involved at all. Humans don't have to review all of the content, just the stuff the algorithms are unsure about, as well as takedown/review requests.
Content ID, on the other hand, is a problem of their own making.
It's possible that it's impossible to do any better than they currently are, but as we don't have access to all of the data that they do, we cannot make that determination.