Agents doing retrieval has been around for quite a while

https://huggingface.co/docs/smolagents/en/examples/rag

Agentic RAG: A More Powerful Approach We can overcome these limitations by implementing an Agentic RAG system - essentially an agent equipped with retrieval capabilities. This approach transforms RAG from a rigid pipeline into an interactive, reasoning-driven process.

The innovation of the blogpost is in the retrieval step.

Vector search has moved from a "complete solution" to just one tool among many which you should likely provide to an agent.