The core observation is that organisms with an ability to model the Universe, even if imprecisely and in a tiny space-time neighborhood, increases the chances of survival. See the ubiqutous living beings with a nervous system. The hypothesis is that increased precision and/or size of the prediction bubble is correlated with survival fitness, which, in the limit, gives raise to beings with a God-like ability to predict the Universe. It's a relatively simple inductive argument.
Even if it is true that "in the limit" increased foresight implies increased fitness, it doesn't necessarily follow that being with God-like foresight exist.
That said, IMO there's a lot of things that could confound the usefulness of increased foresight. After a certain point (which humanity has likely passed) foresight is not a particularly visible measure of fitness except in those rare extinction events that require significant cooperation to survive. I suppose that even given that foresight is the most valuable trait for long-term survival of a species, it's very rare that it is selected for beyond a certain point because the events that it allows a species to survive are too rare to be selected against.
