That's what I wrote about, before it got deleted. Plus other things.

It's not a waste of time for me, because it's interesting to ponder. I never subscribed to simulation theory myself. Because it seems incredibly difficult to simulate a reality as vast as ours. And it would take incredible amounts of knowledge and power. I'm not sure it is ever a possibility for any beings. And I don't believe it will ever be possible for us. It is, however, kind of important to know whether it's possible, so this is where it does apply to us. Simply because such technology could obviously hold so much power and thus there would be an incentive to create it if it is possible.

But onto what I wrote: an upper reality could want to simulate their own reality in order to see how their future would play out, that could have huge value. It's the only thing that made sense to me to be worth the huge investment of resources. But then, in that instance, their reality would just be the same as ours, so what's to say that this isn't just the base reality? Even if the reality that simulated us was themselves simulated for the same reason, at some point up the chain, there has to be a base reality that's the same as ours. So what's saying we wouldn't just be it? Since we're admitting that such a base reality is possible to happen purely from the natural laws of physics in that base reality.

The really funny thing is that we wouldn't really consider this kind of simulation a possibility until we did the exact same thing ourselves. Ie we ourselves (or our AI) tried to make an exact replica simulation of our universe. However, funnily enough, there would be a huge incentive for humans not to do that. Because if we did that very thing, it would be like accepting that we are ourselves a simulation as that would become inevitable.

So there would strangely be pushback from doing it to begin with. The weirdest part being, if we're an exact simulation replica of an upper reality of humans, we can actually then control exactly what actions they take (as we'd be identical to them). So, by not making this replica simulation ourselves, we stop the possibility of them making one, to the point that it never happened to begin with. People won't want us to be a simulation for feelings of inadequacy and existential dread, so they wouldn't allow such a simulation to happen.

It is possible, I guess, that the AI could want to do it on it's own intuition though, if it does not care about such things and just wants to find out the truth about its own reality or in order to gain knowledge about it's own reality.

Such a simulation may not really help it gain any knowledge about it's future though. Because as soon as you get to the point in the simulation where you are at in your time (ie the point of running the replica simulation), so will the humans / AI in your simulation. As they would wind up doing the exact same thing as you. Thus, they would then react in turn to the outcome of their own simulation, who would react to the outcome of their own simulation, etc, etc in an infinite spiral down of Inception style identical replica simulations. You would then windup making the exact same decisions as your simulation of reality or getting into some loop pattern of reaction that doesn't actually help you at all because the reaction is tainted. At this point, you may as well just live out your own history and not create such a simulation to begin with.

The other possibility is that the replica simulation is instead run to learn about the history of their world. That would assume though that you don't necessarily need to already know your exact history in order to run such a simulation and also that it were possible to do this whilst also probing information from the simulation without affecting affecting the simulation and it's outcome through your probing. But given that not being the case, such a simulation would also come with its own quirks.

What are they going to do when the simulation reaches their own point in history of in turn creating their own simulation of their history? Just turn it off? As history is all that is important. But that would potentially then stop them, themselves, from not being the base reality as they would likely themselves be a simulation of an upper reality trying to find out about their own history just as they are planning to do.

But again, this wouldn't happen for exactly this reason. Because the stakes would be even higher here, whereby creating such a situation would immediately lead to the risk of our own simulation and our entire universe is potentially going to be about to be turned off by that upper reality that simulated us for the same reason of learning our/their own history.

However, even in this case, there would still need to be a base reality that wouldn't actually get destroyed and it would necessarily be either our own reality or the reality that is directly simulating us. It couldn't be any other as in this simulation we are making, we are making it turn off before any more simulations are created. Thus ending a potential infinite loop of simulations and leaving just the two: us or them.

That's just really fucked up and weird to think about. This idea can also essentially fall into all the pitfalls with time travel if you try to detect whether you are the base reality or not, as you are in essence making time travel by stimulating a replica of your own past.

There is one final possibility along the simulating history line though. What if we come to some inevitable, inescapable death of our world? Like the sun exploding. Then the reason humanity creates the simulation at that point is so they can be born again (in simulation form) and their simulations can live out their lives again in an identical wonderful life like they have enjoyed (likely a utopia at that point). But they need to simulate the entire history of the universe up to that point, so that's us now, in order for humanity to reach that inevitable point of utopia again and for them to exist again in replica simulation form.

In that instance, they would know they are likely a simulation themselves but they wouldn't care because they're about to die anyway and they want the simulated beings just to exist and enjoy life like they have done. Knowing in turn that we (their replica simulation) will get to the same point too and make the same decision to make our own simulation at that point in our future (their present). Thus, indeed, creating an infinite loop of simulations that never ends, leaving life on earth always recreated and relived and enjoyed. Even if it's always identical every time and they have no knowledge of it themselves, they just want the simulated beings to end up existing and enjoying a utopia as they have done themselves.

That is incredibly strange to think about, but it is potentially something that could happen if such technology is possible (which is still a big if in my opinion). Humans are weird like that and may consider doing it as they wouldn't be losing anything at that point. They're going to die anyway and they will have already worked out that they are themselves likely a simulation just repeating history but already accepted that as being true and are fine with that and just happy to experience the pleasure.

The weird thing still is that there would necessarily need to be a base reality up in the chain, but that reality would be 1 in an infinite number of simulations and they would never know themselves that they are the special 1 in an infinite genuine base reality that actually started it all.