That's not what LLMs are, but it's a marketing buzzword in the end I guess. What you linked is a transformer based sequence-to-sequence model, exactly the same principal as ChatGPT and all the others.

I wouldn't say it is a good use of AI, more like one of the few barely acceptable ones. Can we accept lies and hallucinations just because the alternative is nothing at all? And how much energy/CO2 emissions should we be willing to waste on this?