Comment by jillesvangurp

Or when you care at all about optimizing your search ranking. Postgresql has a few alright tools to do vector search and to do some simple things with trigrams. And that can work well for some narrow use cases. If that's all you need, great. But this doesn't give you a whole lot of control over search ranking. And if search is in anyway on the critical path to revenue for whatever it is your product does, you probably need to invest in making sure your users find what they need. And that means getting a bit systematic about things, using specialized tools, and making sure you have some skills on your team that know how to do this.