In the Copenhagen interpretation, the wave function represents our ignorance of what the system's state will become when observed, but it's taken as an accurate

In the Copenhagen interpretation, the wave function represents our ignorance of what the system's state will become when observed, but it's taken as an accurate description of the system's actual state prior to observation. That is the point of the "Schroedinger's cat" paradox: that under the Copenhagen interpretation, the cat actually is in a superposition of alive and dead states, until someone looks in the box. Quantum computation crucially depends on the objective reality of this superposition. It seems likely to me that the superposition in the formalism actually just represents our ignorance of the system's state, not the state itself.