Well the beauty of the actual system is that you don't need a "natural observer" until you have one. You calculate the time-evolution of the system with non-collapsing wave functions, then you collapse the wave function only when an observer finally shows up to make the observation.
It doesn't matter if the wave functions were waiting billions of years to finally be collapsed, you are not missing anything by not having collapses before you have natural observers.
actual system
meaning the standard QM interpretation?
It doesn't matter if the wave functions were waiting billions of years to finally be collapsed, you are not missing anything by not having collapses before you have natural observers.
But consider the first natural observer, composed of matter. At what point do the wave functions associated with that matter collapse? Before or after its first observation?
With decoherence & MWI, this question presents no problem.
How many universes "branch off" from a "quantum event", and in how many of them is the cat dead vs alive, and what about non-50/50 scenarios, and please answer so that a physics dummy can maybe kind of understand?
(Is it just 1 with the live cat and 1 with the dead one?)