A sitemap tells readers where pages live. A graph tells you how they relate: which pages are orphans, which ones hold the network together, and whether a reader can actually get from a question to a finished task.
Technical documentation is like a garden, and it grows in three stages. The wasteland has no process and no owner. The English garden is cultivated but informal. The French garden is structured and deliberate. Knowing which one you’re standing in tells you what to fix next: and what not to.