It's a beautiful nightmare, isn't it?
> whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame.
But What I don’t understand about this is why is “time” framed as observer based? In my mind, the events do happen at the same time and just are unable to be observed as such. I feel like time is a figment of our imagination, it’s just a measurement. In my pea brain time makes sense more as a constant and the other things are something else that impacts the latency of observance
Not so, I would say.
Space and time are inherently linked under special (and General) relativity. For two observers who have relative motion between them, the space (distance between two 'events') and time (between the said events) are both different.
When some poem or a song talks about the universe being frozen at a given instant of time, that can be only in a given reference frame. There's no absolute time for the universe.
Its a logical consequence of the speed of light being constant in all inertial reference frames, regardless of the velocity.
This is an axiom of special relativity, but it has also been verified at (admittedly low) relative velocities.
That in itself is somewhat absurd, but it leads to further absurdities when you do the math. In order for the speed of light to remain invariant, you can no longer speak of an absolute (preferred) frame of reference.
You can of course, privilege certain reference frames e.g. Earth, but its rather arbitrary.