I think we will find this not to be the case. And of course, many people like me do think that the ability to predict well enough implies the ability to do everything else.
Since I wrote my reply, I found two other posts on HN that seem relevant to that if you want to read more:
AI vs. AGI vs. Consciousness vs. Super-intelligence vs. Agency https://secondbreakfast.co/ai-vs-agi-vs-consciousness-vs-sup...
Simulators (Self-supervised learning may create AGI or its foundation) https://generative.ink/posts/simulators/
Here is a quote from that last one - I am still reading it since it is long, but
> ... I call this the prediction orthogonality thesis: A model whose objective is prediction can simulate agents who optimize toward any objectives, with any degree of optimality (bounded above but not below by the model’s power).*
> This is a corollary of the classical orthogonality thesis, which states that agents can have any combination of intelligence level and goal, combined with the assumption that agents can in principle be predicted. A single predictive model may also predict multiple agents, either independently (e.g. in different conditions), or interacting in a multi-agent simulation. A more optimal predictor is not restricted to predicting more optimal agents: being smarter does not make you unable to predict stupid systems, nor things that aren’t agentic like the weather.