> Any verification process thorough enough to catch all LLM fabrications would take more work than simply not using the LLM in the first place

Sometimes you have a weak hunch that may take hours to validate. Putting an LLM to doing the preliminary investigation on that can be fruitful. Particularly if, as if often the case, you don't have a weak hunch, but a small basket of them.

You can prompt LLMs to scan thousands of documents to generate text validating your hunches. In some cases those validated hunches may even be correct.