A very quick but sufficient refutation is that the same math taken as a description of an objectively existing causal process gives us MWI, hence there is no reason to complicate our epistemology beyond this
Or MWI could be said to be complicating the ontology unnecessarily. To be sure, rQM answers epistemologically some questions that MWI answers ontologically, but that isn’t obviously a Bad Thing. A realistitc interpretation of the WF is a postive metaphyscial assumption, not some neutral
default. A realistic quantum state of the universe is a further assumption that buys problems other
interpretations don’t have.
Or MWI could be said to be complicating the ontology unnecessarily. To be sure, rQM answers epistemologically some questions that MWI answers ontologically, but that isn’t obviously a Bad Thing. A realistitc interpretation of the WF is a postive metaphyscial assumption, not some neutral default. A realistic quantum state of the universe is a further assumption that buys problems other interpretations don’t have.