For a multi-particle system, superposition is in some sense equivalent to entanglement; with the Dirac field being treated as classical under second quantization, for example, we could at least argue that any simple tensor product of single-particle states (whether or not they are spatially localized!) corresponds to a single physical reality, and thus does not contain meaningful superposition. Superposition in this context is rather the necessity for the overall state to be written as a sum of such tensor products, that is, entanglement.
In this vein, here's my question: are we really sure that a complex macroscopic object, when evolved via quantum field theory, approaches a highly entangled state? Or is it possible that it actually tends to a separable one? Like, maybe it tends to a product of states that are fairly well, though not perfectly, localized, much like typical atomic orbitals. In this case you wouldn't need an objective collapse theory to explain the quantum to classical transition.
