What is currently considered the state of the art when building things like this? I've heard people find RAG not to work very well, is that accurate? Is it jus

What is currently considered the state of the art when building things like this? I've heard people find RAG not to work very well, is that accurate? Is it just about using the right embeddings? I suppose ideally you just put the sources in the context window, which becomes limiting with large amounts of text?