Long tail, coping with typos, and understanding negation.
If natural language was as easy as "enough patience to write down a hundred patterns to match", we'd have had useful natural language interfaces in the early 90s — or even late 80s, if it was really only "a hundred".
For narrow use cases we did have natural language interfaces in the 90s, yes. See e.g. IRC bots.
Or to take a local example, for more than 20 years my city has had a web service where you can type "When is the next bus from Street A to Road B", and you get a detailed response including any transfers between lines. They even had a voice recognition version decades ago that you could call, which worked well.
From GP post, I was replying specifically to
> LLMs in data pipelines enable all sorts of “before impossible” stuff. > For example, this creates an event calendar for you based on emails you have received
That exact thing has been a feature of Gmail for over a decade. Remember the 2018 GCal spam?
https://null-byte.wonderhowto.com/how-to/advanced-phishing-i...