The biggest added value is that it works. Before LLMs we tried all kinds of stuff, including purely statistical methods, and anything more complex than scripted

The biggest added value is that it works. Before LLMs we tried all kinds of stuff, including purely statistical methods, and anything more complex than scripted responses was incredibly hard to keep coherent for more than five sentences. GPT2 had similar issues, but modern LLMs are incredibly good. But ultimately the goal are models that have a decent world model and can reason about it. A model that you can ask for a python program that does something completely novel, and you get a working result. We are somewhere on that road, far beyond what we were able to do with statistical methods but still not nearly as good as we wish.