That you can place Nostr events in it in a form that is natural and organic. That you can let the data form itself into the structures that emerge organically by the network that creates it. And that it gives you the right tools to find things you couldn't imagine before you started.
That is why graph data is powerful, and why it outstrips tables and other databases in my mind. There's power in it's inefficiency because you can build on it indefinitely. You set yourself up to build things you can't imagine instead of constraining yourself to what you're building today.