When it comes to pointing out the unreliability of LLM/image/video gen in the sense that it destroys the usefulness, it seems to me that people forget that unlocking the phone with your face or fingers is just as reliable, but as we see, it is used often.

Why is regular deep learning accepted despite its unreliability, but LLM for some reason isn't?

Facial recognition is also widely used in forensics, with the enormous cost of error. And although people often object to it, for some reason almost no one say that it's useless. In most cases, people are content that it's not the most important piece of evidence, given the potential for error.