See, I don't get why people say that the world is somehow more complex than the world of mathematics. I think that is because people don't really understand what mathematics is. A computer game for example is pure mathematics, minus the players, but the players can also be modelled just by their observed digital inputs / outputs.

So the world of mathematics is really the only world model we need. If we can build a self-supervised entity for that world, we can also deal with the real world.

Now, you may have an argument by saying that the "real" world is simpler and more constrained than the mathematical world, and therefore if we focus on what we can do in the real world, we might make progress quicker. That argument I might buy.