Comment by thomasmg
3 hours ago
(This is way beyond my area of expertise so excuse me that this might be a stupid idea.)
I assume the following happens: while a (small) subsystem is in "pure state" (in quantum coherence), no information flows out of this subsystem. Then, when measuring, information flows out and other information flows in, which disturbs the pure state. This collapses of the wave function (quantum decoherence). For all practical purposes, it looks like quantum decoherence is irreversible, but technically this could still be reversible; it's just that the subsystem (that is in coherence) got much, much larger. Sure, for all practical purposes it's then irreversible, but for us most of physics anyway looks irreversible (eg. black holes).
The problem is that the larger subsystem includes an observer in a superposition of states of observing different measured values. And we never observe this. Copenhagen interpretation doesn't deal with this at all. It just states this empirical fact.
So if I understand correctly, you are saying the observer doesn't feel like he is in a superposition (multiple states at once). Sure: I agree that observers never experience being in a superposition.
But don't think that necessarily means we are in a Many-Worlds. I rather think that we don't have enough knowledge in this area. Assuming we live in a simulation, an alternative explanation would be, that unlikely branches are not further simulated to save energy. And in this case, superposition is just branch prediction :-)