> The model itself isn't separate from the world but produced materially

To me this is like drawing a circuit diagram on a piece of paper and trying to convince someone that, "Really there is electricity flowing through it."

Models are relations between signifiers. There exists a transformation between the signified relations and the relations of the signifiers, but they are, in fact, two separate categories and the transformation isn't bijective. ie it doesn't form an isomorphism.

A map drawn on a flat piece of land is still not the whole land it depicts, even though it literally consists of that land. Any representation is a simplification, as much as we can judge, there's no adequately lossless compressing transform of large enough swaths of reality.