I'm not sure if I would want to say "a knowledge graph of the world" is the "key to true AI".
I think the situation is closer to "true AI is the key to a usable if situationally depend knowledge graph". Because the world doesn't have single knowledge graph that you can learn and use in all situations. Certainly, you can find a lot of common instances where the average works but once you're past that, you need the kind of understanding of language that present day systems are far from having.
"Because the world doesn't have single knowledge graph that you can learn and use in all situations."
The logical way to overcome this via a "data first" brute force approach is to build personalized knowledge graphs of every potential customer. Which is in effect what every statistically sophisticated large business is attempting.
I think the situation is closer to "true AI is the key to a usable if situationally depend knowledge graph". Because the world doesn't have single knowledge graph that you can learn and use in all situations. Certainly, you can find a lot of common instances where the average works but once you're past that, you need the kind of understanding of language that present day systems are far from having.