Yes, I think you put your finger on it. As the observer is part of the system, his "reality" is as much superposed, entangled, etc., as the quantum events that compose it (himself and his observation too).
That would give credit to the multiverse interpretation of quantum mechanics then.
Maybe the observation process of a quantum phenomenon by a human observer is akin to the orthogonalization of a matrix:
as the observer becomes entangled with the observed particle, each possible observer-eigenstate (i.e. any observer in "his reality") ends up observing an eigenstate of the observed quantum phenomenon, instead of a dirty superposition.
To call it "orthogonalization of the observer-observed system" would be more descriptive than "wave-collapse", but the main difference is that the orthogonalization treats in parallel all possible outcomes, each linked to a different state (outcome) of the observer too, whereas the "collapse" view insists on the fact that the observed eigenstate is unique. And moreover, at least in mathematics, there are conditions for the orthogonalization to be possible at all, so that should be interesting.
That would give credit to the multiverse interpretation of quantum mechanics then.
Maybe the observation process of a quantum phenomenon by a human observer is akin to the orthogonalization of a matrix:
as the observer becomes entangled with the observed particle, each possible observer-eigenstate (i.e. any observer in "his reality") ends up observing an eigenstate of the observed quantum phenomenon, instead of a dirty superposition.
To call it "orthogonalization of the observer-observed system" would be more descriptive than "wave-collapse", but the main difference is that the orthogonalization treats in parallel all possible outcomes, each linked to a different state (outcome) of the observer too, whereas the "collapse" view insists on the fact that the observed eigenstate is unique. And moreover, at least in mathematics, there are conditions for the orthogonalization to be possible at all, so that should be interesting.