They might not have had experience 2 years ago, but in the meantime they assisted 100s of millions of people for many billion tasks. Many of them are experiences you can't find in a book. They contain on-topic feedback and even real world outcomes to LLM ideas. Deployed LLMs create experiences, they get exposed to things outside their training distribution, they search solution space and discover things. Like AlphaZero, I think search and real world interaction are the key ingredients. For AZ the world was a game board with an opponent, but rich enough to discover novel strategies.
