That’s not what I’m saying. My point is just that observation = interaction has a lot of implications. Particles are always interacting, so if the wave function represented some absolute state of all systems, then the statement would just be incorrect because the wave function would be incapable of ever “spreading out” as it is constantly interacting with a lot of things.

The only way it can be made consistent is to then say that wave functions are not absolute things but instead describe something relative to a particular system, sort of like how in Galilean relativity you need to specify a coordinate system to describe certain properties like velocity of systems. You pick a referent object as the “center” of the coordinate system which you describe other systems from that reference frame.

You would have to treat the wave function in a similar way, as something more coordinate than an actual entity. That would explain why it can differ between context frames (i.e. Wigner’s friend), and would explain why you have to “collapse” it when you interact with something, as the context would’ve changed so you would need to “zero” it again kinda like tarring a scale.