Basically the LLM may make people’s jobs easier, for instance someone can get a meeting summary with less effort, but they produce worse results if you consider everyone affected by the work product, like considering whose views are underrepresented in the summary. Or, if you’re using it to categorize text, you can’t find out why it is producing incorrect results and improve it the way you could with other machine learning techniques. I think Emily Bender can do a better job explaining it than I can:

m.youtube.com/watch?v=3Ul_bGiUH4M&t=36m35s

check out the part where she talks about the problems with relying on LLMs to generate meeting summaries and with using it to clarify customer support calls as “resolved” or “not resolved”. I tried to get close to that second part since the video is long.