Because MWI needs perspective-independent objectivity, that it is meaningful to describe reality with “a view from nowhere”, as the universal wave function does. So it needs to accept the postulate in Step 3. CI could (and I argue should) do without. No matter how commonly accepted it is, Step 3 is still an assumption.
Because MWI needs perspective-independent objectivity, that it is meaningful to describe reality with “a view from nowhere”, as the universal wave function does. So it needs to accept the postulate in Step 3. CI could (and I argue should) do without. No matter how commonly accepted it is, Step 3 is still an assumption.
I deny that MWI requires that. In fact, all three of your postulates are incoherent, and I believe in a form of MWI that doesn’t require any of them.
Fair enough.