Having used vectorDBs before, we're very much not there yet. We don't have any appreciable amounts of context for any reasonable real-life memory. It works if that is the most recent thing you did. Have you talked to an LLM for a day? Stuff is gone before the first hour. You have to use every trick currently in the book, treat context like it's your precious pet
VectorDBs are basically just one excuse of many to make up for a part of the system that is lacking capability due to technical limitations. I'm currently at 50:50 if the problems will be overcome directly by the models or by such support systems. Used to be 80:20 but models have grown in usefulness much faster than all the tools we built around them.
