That’s a misunderstanding. Decoherence theories do not “introduce” the UWF; it’s already there in standard QM. What decoherence theories do is they discard the metaphysical superstructure of “collapse”, whereby branches of the UWF somehow (inexplicably) disappear, a-causally, and then get ignored. Decoherence theories are more elegant and parsimonious on a theoretical level, which is why they are preferred by many. As an example, please explain succinctly in a couple of sentences what causes the collapse of UWF in standard QM, and /or when it collapses, without using ill-defined terms such as “observation”. The “measurement problem” has never been resolved in collapse theories, it just gets swept under the rug. PS, I do not believe the pilot wave theory has been disproven. However it does indeed introduce some rather questionable entities, the “beables”.
