Since the scalar product is the only internal structure of a Hilbert space, all vectors of norm 1 are equivalent, in the sense that they form a perfect sphere in the Hilbert space, on which every vector looks the same. The state vector of the universe contains no information that distinguishes it from other state vectors of the same Hilbert space. If the state vector is considered as the only fundamental entity, the world is completely structureless. The illusion of interacting subsystems is due to a bad choice of factorization (i.e. decomposition into subsystems) of the Hilbert space. There is always a more appropriate factorization available in which subsystems dont interact and nothing happens at all. This factorization absorbs the time evolution of the state vector in a trivial way. The Many Worlds Interpretation is therefore rather a No World Interpretation. A state vector gets the property of representing a structure only with respect to an external observer who measures the state according to a specific factorization and basis.
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