Great article. I was recently wondering why are vector databases useful at all. There are cases (LLMs) where they are useful. But apart from that, most of the cases I have encountered, requires indexing on different data types than vector. I might be biased due to my experience but in a very typical use cases e.g. analyzing event streams or building recommendation engine you want to filter rows by timestamp and client id or product category and availability. Vector index is not that useful in those cases.

That's why I think that outside some very specific use cases vector databases are not very useful.