To me the RAG hype is just the sudden rediscovery of information retrieval by money hounds that did not care about AI/ML for decades and now are in panic mode due to FOMO.
There's hype and FOMO for sure and you're right that there's lots to learn from information retrieval work. But why be dismissive of the whole thing? People learning from past research and applying it in new contexts seems like a good thing and there's people (like https://x.com/bclavie and https://x.com/jobergum), who are legit experts in information retrieval and are showing how to apply it to RAG properly.
There are knowledgeable people out there with excellent use-cases for RAG, to find data that is relevant. And they come from years of using the previous state of the art techniques in information retrieval. They have all my support and I am looking forward to read more about it.
But the majority of talk about RAG is coming from hype driven individuals that produce low merit and uninformed opinions.