If we ever have the means to accurately simulate reality - which we already do, at small scales and with significant time dilation - then it becomes almost inevitable that we reside within a simulation, as the simulations would vastly outnumber physical reality, and therefore the balance of probability is that we reside within a simulation - possibly nested within many other layers of simulation.

It isn’t necessary to simulate an entire universe at utter fidelity - just that which is observed - which rather neatly ties into the current understanding of quantum mechanics, and waveform collapse. It also isn’t necessary to do it in realtime, as from within the simulation all would appear synchronous regardless - aeons could pass between states, while the substrate orbits a white dwarf whiling away the cold eternity at the heat death of the parent universe.

Whether that implies an afterlife is another matter - perhaps we are ephemeral after all - but taking Gödel’s argument about the wastefulness of imbuing consciousness only to then snuff it out, half baked, it would stand to reason that any simulator would seek to accrue that experience, and use it for other purposes.

Perhaps there is only one consciousness, asynchronously living every life, every existence. I find this useful to bear in mind, as the person to whom I am asshole today may be an aspect of me from another iteration.

I prefer to look at this not as woo-woo, or belief, but rather logical deduction based on sound premises.

Of course, it may all be bunkum, and we may be alone in the universe, and life may indeed be meaningless and fleeting - but we cannot know, as that would foul up the simulation no end.