Philip Jose Farmer explored this idea in a few of his stories.
In one there was an alien race. They thought it was tragic that people would die and be gone from the world forever. So they invented an artificial soul (called a “wathan”) and hooked it up to all the sentient beings. Then they managed an artificial afterlife too. Reincarnated everybody.
A natural internet maybe. Discarnate dreamers drifting around, talking, looking for fun, spaceless, bodiless, timeless. Until a really good game catches your eye. And then there are rules.
When you dream at night your dreams tend to take the form of your fears, obsessions, desires, hangups, big emotions etc. But you return. The physical world could be called a moderator. It keeps you from descending too far into your personal dreamworld.
But then you die. Same dreamworld, but no moderation. You troll yourself to exhaustion. Might take a million years. Then the physical world draws your attention again, or something.
In greek mythology there’s a forest in the afterlife. Each tree is a soul locked in a catatonic dream-passion. Each fugued out in his personal hallucination. The forest is vast.
My copy lives forever. How does that bear upon me?
There’s got to be a connection between identical systems. That just feels right. A kind of perfect sympathy. And add consciousness to the mix and it seems inevitable.
And given that there will always be infinite cases of total entropy reversal, there will always be a “plausible narrative” for resurrection available for every corpse. So if “immortality via copy” doesn’t do it, that will.
Here are 2 authors who explored the impossibility of subjective death. IE while everybody else sees you die, you actually travel to a universe where your survival is explained by a plausible narrative (and progressively less plausible). Or thereabouts.
GREG EGAN. Permutation city. He called it “dust theory”
ROBERT CHARLES WILSON. Divided by Infinity (in “The Perseids and other stories”). I forget what he called the theory.
Any exploration into strange realms of life, memory or consciousness (and there have been many of those) might shed useful light on the subject for speculation.