>all you need to do to make an agentic RAG is to have the LLM be able to write/rewrite its own search queries (possibly in multiple passes)

I think this is a huge oversimplification, the term "search query" is doing a lot of heavy lifting here.

When Claude Code calls something like

  find . -type d -maxdepth 3 -not -path '*/node_modules/*'

When you give the agent the ability to query the nature of the data (e.g. hierarchy), and not just data itself, it means that you need to design your product around it. Agentic RAG has entirely different implementation, product implications, cost, latency, and primarily, outcomes. I don't think it's useful to pretend that it's just a different flavor of the same thing, simply because at the end of the day it's just some text flying over the network.