yeah, but the bigger the corpus the more you are relying on the LLM guessing the right keyword, if there is no reranking in place, you will just end up burning through a lot of tokens.

coding agents is a very "niche" use-case where lexical matching works very well. code is a graph, by looking at few lines of code you can guess naming conventions etc. codebases are small compared to knowledge bases.

the bigger your index, the more you will need way better tools such as search.