Semantic Search Needs Structure

Dense retrieval finds text near your query in embedding space — which is 'text about similar things', not 'text containing the answer'. Ask 'who succeeded the CEO who resigned in the scandal' and top-k returns scandal coverage and succession coverage — none necessarily naming the successor.

The query contains a relation hop — CEO → resigned → successor — that similarity can't express. This is the failure class that turned GraphRAG from a paper into a product category.