" Within the realist approaches, I believe there is a case to be made that Everett’s hypothesis is the least progressive—although there are arguments on both sides. An enormous effort has gone into developing Everett quantum mechanics, much of it technical and extremely clever, but most of that work has gone to addressing problems that arise only in the Many Worlds Interpretation, but do not trouble the other approaches. I might suggest that the Everett program is, of the realist approaches, the least open to the possibility that future discoveries will lead us to modify the principles and the mathematical formalism of quantum mechanics. "

― Lee Smolin , Einstein's Unfinished Revolution: The Search for What Lies Beyond the Quantum