
I do not understand how not knowing about the origin of life can be used to conclude that we are living in a computer simulation. This is because computer simulations are not created out of nothing. They are usually created by a team of developers for financial purposes. This should also make one wonder about the origin of the theoretical developers as well.
Do you think there is someone external to the universe who actually profits from our "computer simulation" in which we live? If there is someone or a group of entities who do, then there should also be customers who buy this simulation as well, and play alongside us, AKA, the non-player characters who completely live within the product that is the universe.
However, these customers should still have the ability to play in this assumed simulation, while having lives beyond the simulation. Why would there be a virtual simulation where no external players play in it?
This contradicts the assumption that we are in a simulation because why else would this reality be necessary to exist, to be lived in, if no users/consumers interact with it? Surely the reality-running servers would have already shut down, like any other product that is not cared about enough to be consumed enough to generate a reasonable profit.
(2023 Edit: I think it is important to note that the simulation hypothesis is just that, a hypothesis. There is no scientific evidence to support it, and it is ultimately up to each individual to decide whether or not they believe it. Opinions, by the way, can also be deemed as hypothesis. Because they can be either right or wrong.)
And even if there were players who bought this video game, what form would they embody, and what is their role in the game? They cannot be humans or animals, because humans and animals are not NPCs; we have self-awareness whereas NPCs do not, as they are programmed, by their entirety, in a predetermined manner, without a shred of independent thought or action.
They (the players who connect to this reality) could be silent objects which have no self-awareness, but why would being a rock or a table be considered a simulation, or at least bring financial success to the developers? Who would want to play as an inanimate object in a reality of, theoretically, endless possibilities?
Regarding the assumption that we are not NPCs, then we are the players, apparently. However, players have their external lives beyond the game itself - families, other hobbies, jobs, need to eat and so forth, while we are "stuck" in this reality, with death being the only way to log out from this simulation. We humans (and animals) have no needs which are external from our own existence, whereas gamers have. Even an addicted gamer who plays for days on end has a life which is external of the universe, along with other needs. If we had external lives out of this so-called simulation, then we would be aware of that life.
For example: if we suffer from backaches, this suffering is happening inside our simulation, not externally. A bigger problem would be the claim that there is a separation between the player and their character. Our lives are not like the Sims series, where there is an external entity (in the form of a crystal in this case) which tells us what to do.
We are either told by others or by our own will what to do. When we want to do something, that will belongs to us (or inspired by others), not to an external puppeteer. If there was an external puppeteer then they could remove you from the simulation without an in-game reason (people don’t just disappear into the void).
Also consider the following: There is no lag in our reality, you cannot save, load or quit (unless you die, and incarnation is in doubt), you do not need a password to access your life, you cannot create your own character inside the game (as humans are created by sexual intercourse and other ways which have no out-of-reality control).
You cannot change an assumed player’s behavior by breaking the fourth wall constantly, you cannot hack into other characters/accounts and control them completely as if you've invaded their neurological system like a hacker to a remote computer, there are no cheat codes (you cannot get a million dollars instantly without an in-game reason) and you cannot pause time or control it in any other way, with "killing time" merely being an expression of a subjective experience.
Because of all the reasons I just mentioned, I find it hard to believe that we are actually living in a computer simulation. Existence does not contain the components and traits that are often found in actual computer simulations. Even if we are to assume that we indeed live in such a framework, why do we need to be in a simulation and not the simulating, external reality?
Are realities infinite in a sense that one of them is being simulated by the one before it, and/or simulates the one after it? Where does it begin, where does it end? Has it ever begun, will it ever end?
After all, nothing lasts forever but the void, not even the simulation of things and beings, which contains said void. The void doesn't go away, but stays permanently whether or not it had an origin like anything else non-void.