This is why I think Vector DBs are probably not going to be used for a lot of applications in the future. It served a very valid purpose when context windows were a lot smaller and LLMs were not as good, but moving forward, I personally think it makes less and less sense.
Vector DBs will still be around to do a first pass before feeding data in to a long context reasoner like Gemini in most cases. The thing that's going to go away is rerankers.