No, I fully understand what is meant by first mover, I'm merely pointing out that the first mover in a chain of simulations could have the same characteristics as a theological first mover
A simulation requires a computer. As far as we know, computers don't come into existence from nothing but they are made by living beings who have arms and brains. A theological first mover is spaceless and timeless. It's formless. Computers have a form. They are in space. They are bound to time.
There is nothing about simulation theory that is inherently atheistic or theistic. You could believe we are the first in a chain created by a higher power, while at the same time acknowledging that our current technological trajectory indicates creating a simulated universe will one day be possible. By the same token, you can believe that we are not the first in this chain, but that the origin point remains a classic higher power. Thus, the two theories are not mutually exclusive. As I mentioned before, an eternal creator could be civ prime. At a certain point, simulation theory blends atheism and theism, because from a created civilization's perspective, their creators would appear to have all of the properties of a God.
No, those creators wouldn't have all of the properties of a god. They wouldn't be the first mover. They wouldn't be eternal. Especially if there is a longer chain, then our direct creators wouldn't definitely be the first mover and they wouldn't be eternal as they have been created by someone else. And they would be material beings, or at least the computer that runs them would be material, or at least the first computer in the chain (as the computers in each of the simulation is just a computer program) would be material.
Simulation theory acknowledges that a prime biology would have to originate the simulations, and it makes no attempt to explain such a biology. It is entirely separate from theological debate. From the simulation theory perspective, this prime biology could be so different from ourselves, so far removed from our understanding of our own universe, and so advanced, that speculating it's origins or intentions would be pointless
The existence of biology already makes it completely different from how Jews, Christians and Muslims have defined god.
The theory makes a claim that it is a computer simulation though and the reason for the theory to exist in the first place is the speculation of us eventually being able to run a simulation like this.
And as soon as you start to bring out the ideas of the prime biology being so completely different from our universe the whole thing kinda loses its point.
And surely you see how you are now holding one paradigm to higher standards than another? Abrahamic religion can be started by something that isn't physical or temporal and breaks all scientific rules as we understand them, but a civ prime can't? A civ prime would inhabit a universe prime, which may have entirely different physical laws than our own universe. What you are describing as God is abstract and unprovable. The exact same logic could be attributed to higher dimensions, alternate universes, simulations, etc. We simply don't have enough information beyond our own universe to favor any of these theories heavily
I'm just comparing one idea to another. The other has always been spaceless and timeless, transcendent from our reality of space and time. The other one has a computer simulation with material beings creating the simulation. They can't be the same no matter how much you'd like to twist them to be.
This spaceless and timeless view of God has been around ever since people started to think what the hell happens when we dream, have out of body experiences, think we hear voices, see visions, have near death experiences - which means it has existed pretty much all of our existence.
This simulation view has first required us to create a computer and then wait quite a bit to see how computers advance and see people make simulators.
At least the older view of god tries to explain the experience of self. The simulation theory makes a huge leap in trying to fit our personal sense of self into a computer program. It basically makes the claim that at some point in time not only the simulation would be amazingly complex in a programmers point of view but that the programmed NPCs are each having a sense of self in the program too. So far absolutely nothing points to computer AI being able to sense their self and have the experience of being. Even the most convincing robots today have zero sense of self. They don't experience their being at all. They are as understanding a brick in a house wall and nothing points out to the direction that they ever will be anything more than that. The only ones who experience the robot's "sense of self" is us who are observing it. We can't ever go and see if the robot is actually experiencing anything.
They could be programmed into having an illusion that they sense themselves, but who is there to witness that illusion? The fellow NPCs don't sense themselves and they don't sense the other NPCs either. The only ones that could be convinced of the NPCs to have any realization of self are the programmers and their friends (if they are not a simulation themselves). The sense of self in a computer program AI can only be observed by their makers and even then they are only seeing an illusion of the AI sensing themselves. Now, I can't know if you sense yourself at all there, but I can notice me being me and I can assume you sense yourself the way I sense myself. The atoms inside of me change. I learn things and I forget things. But even if all my atoms have been constantly changing I can see this sense of self has experienced all of it and no-one else has witnessed it the way I have. To say this experience will once be realized by lines of code in a computer program is way more abstract and unprovable than the idea of god has ever been.
It absolutely could be. But do keep in mind that the probabilities aren't the same. If we are civ prime and we fail to make simulations, there is plenty of time for another civilization in our universe to do so, which would still start the snowballed simulation propagation.
This makes the assumption that there are other civilizations and that they are evolving into something quite like what we have evolved into, and that they have interest in technology or even ever start to make technology. They might not even be interested in stars. They might not even invent a wheel. They might not even use fire to their advantage. Or they could be amazing at building things but they never start using electricity, or they just never create a computer.
And since we don't know why simulations are designed, we don't know if we are even intended to propagate more simulations. Thus the probability we are a simulation would remain high even if we fail, what's important is that such simulations are possible, not that we manage to create one
But are those simulations really even possible? You speculated that the first in chain might have completely different physical laws than our universe. That already goes way beyond saying it could be possible for us to make a simulation when the ones who made the simulation for the ones who made the simulation to the ones who made the simulation for us have things way different than what we have here. We currently have no idea if any computer ever will be able to be so powerful it can make a simulation that feels as real as this world feels, let alone make parts of the code self-aware in the way that they are actually experiencing self the way we now are. If you want to prove that we can make such a simulation, the original world that made the first simulation should be quite like our world too. If it's different, then it doesn't say anything about our possibilities to make similar simulations. And the first computer should be so powerful it can create a simulation that can make another simulation that can make another simulation. At the very least their computer should be powerful enough to make a simulation that has the possibility to make a simulation if you want to think it's possible for us and that we are in a simulation at the same time.