I do not understand how not knowing about the origin of life can came as a conclusion from the claim that we are living in a computer stimulation.
This is because computer stimulations are not created by nothing. They are usually made by a team of developers for financial purposes.
Do you think there is someone external of the universe who actually makes profit from our “computer stimulation” in which we live in? If there is someone or a group of entities which do, then there should also be costumers who buy this stimulation.
However, these costumers should the ability to play in this assumed stimulation. Why would there be a virtual stimulation where no external players play in? It contradicts the assumption that we are in a stimulation.
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 human and animals are not NPCs (non-player characters); we have self-awareness whereas NPCs do not. They (the players who connect to this reality) can be silent objects which have no self-awareness, but why would being a rock or a table considered a stimulation, or at least bring financial success to the developers?
Regarding the assumption we are not NPCs, then we are players. However players have their external lives beyond the game itself - families, other hobbies, jobs, need to eat and so forth. 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 own a life which is external of the universe, along with other needs. If we had external lives out of this so-called stimulation, then we would be aware of that life.
For example: if we suffer from backaches, this suffering is happening inside our stimulation, 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 stimulation 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 forth wall constantly, you cannot hack into other characters/accounts and control them completely, there are no cheat codes (you cannot get a million dollar instantly without an in-game reason) and you cannot pause time or control it in any other way.