For me there's two separate problems:
1. The plagiarism aspect, and that most of the training data was used without permission
2. I haven't found it terribly useful in my personal work, as the data it was trained on was heavily polluted by incorrect information (at least in the field I'm using it)
1. I said in my hypothetical it would not reproduce exact content. 2. Okay, others find it useful. So what?
You shouldn’t be relying on worlds knowledge accidentally captured in model weights, that’s a bug not a feature. Instead you should be stuffing relevant context into your prompt so it has the correct information. You obviously are really confused about how LLMs work and how they should be used.