This is true of base LLM models that are just trained on missing-word prediction on the training corpus, but one of the main points of RLHF[1] is to tune this model to make these kind of inferences the way a human would expect. For example if you asked an untuned model to write a poem in the style of ... etc., a valid internet response might be "hmm no thanks, you go first", you need to steer the model away from replying like this.
I'm not saying it's perfect, but it's wrong to say e.g. GPT-4 has had no information about the difference between a good and bad response and is just generating internet-like text at random, the big players have made progress on this already.
[1] https://en.wikipedia.org/wiki/Reinforcement_learning_from_hu...