Mathematics is just a representation of reality, not the reality itself.
No single law in all scientific fields can state that the law itself is the physical object, or a part of the Universe. One may assert that General Relativity can explain lots of observations we can make about this universe. However, even if the observations match the way the universe seems moving 100%, it doesn't indicate that the universe itself is GR. GR is just a successful model of reality that can assert some important relationships among macroscopic observations in this universe.
Assume that someone forged a ultimate theory that can integrate every possible physical observation we can make about this universe. Even if that's the case, he can't assert that "this universe IS the theory." It's merely the theory is a successful model of reality, but not that reality is model itself.
No one can dare to claim that a set of mathematical description of observation equals reality. No wavefunction can be a physical object. That's simply idiotic.