Your point certainly holds true for any physical entity as far as we know - probabilistic quantum effects, Heisenberg's Uncertainty, chaotic systems, and all that.
However if you were to model a theoretical entity, and given a few more constraints (like strict computability, which precludes a turing-complete systems), you can indeed have correct models. Alas, in practice this is a rather rare example.
Your point certainly holds true for any physical entity as far as we know - probabilistic quantum effects, Heisenberg's Uncertainty, chaotic systems, and all that.
However if you were to model a theoretical entity, and given a few more constraints (like strict computability, which precludes a turing-complete systems), you can indeed have correct models. Alas, in practice this is a rather rare example.