Because this is precisely what the word counterfeit means, an imitation that deceives you. The functionality of counterfeit can be from 0% to 100%, depending on your luck. If you accidentally bought a fake iPhone, it can still make calls. Chat output is something that looks like a literature review, some collection of summaries of relevant papers. But the problem is that a review is not just text compression. It is also about rejecting low-quality research, considering the historical context, identifying contradictions, etc. No machine can do that analysis for you, yet. I have quite a confidence in that.