That's just not true. Semantic encodings work. It's not like neural networks are some new untested concept, the LLMs have some new tricks under the hood and are way more extensive in their training goal, but they're fundamentally the same thing. All neural networks are mimicry machines enabled and limited by their data, but mimicking largely correct data produces largely correct results when the answer, or interpolatable answers exists in the training data. The problem arises when asked to go further and further afield from their inputs. Some interpolation and substitutions work, but it gets increasingly unreliable the more niche the answer is.

While the LLM hype has very seriously oversold their abilities, the instinctive backlash to say they're useless is similarly way off-base.