Yes, practical separation occurs. But you still have to explain why our experience is that of a single outcome when the only thing in the theory (the wave function) says nothing of the kind.<p>Now, this can be rectified by using many worlds, for example. Particularly, integrating out the wave function to get a mass density on 3-space (non-relativistic version) does produce a valid theory which has multiple realities whose evolutions internally would appear to have single outcomes even when that is not actually true. Fuzzy tv reception with multiple overlapping channels is the mental model here.<p>However, that is not just decoherence. One has to add something. And the question is, why choose a theory that denies the truth of our common experience in such a fundamental way when one does not need to do so?<p>Pilot-wave theory is, subjectively, very simple and natural.  It is not epicycles upon epicycles. In fact, quantum theory practically screams out for it with the existence of the probability current and the many insights that that current drives. There are at least 5 very distinct ways to derive pilot-wave theory from quantum notions.<p>One last thing to ponder. Wave functions are defined on the configuration space of the particles. The specific space is crucial to defining the evolution operator. Fermions and bosons emerge naturally by considering the configuration space of unlabeled particles.<p>But if you have no particles, why is a configuration of them useful at all?