I think there are deeper problems in the argument than merely "it would take a lot of resources". I'm concerned by arguments in the form "I can imagine that something is true, therefore it is true". From this perspective, I see the argument like this:
1) (Assume that) we can create a simulation with intelligent beings in it.
2) Therefore, it is not impossible that someone has created a simulation in which we are the simulated intelligent beings.
3) Therefore, it is highly likely that we live in a simulation.
I simply don't get the logical implication between 2 and 3 from "not impossible" to "highly likely". I have the same concerns with the ontological argument for the existence of God:
1) I can imagine a being that is perfect and all-powerful.
2) This being therefore exists, because if it didn't it wouldn't be perfect nor all-powerful.
In both cases I see an extreme case of begging the question.
It's curious that the argument presented by Broston is not "it's likely that we're living in a simulation"; it's an either/or:
Either we're living in a simulation,
OR an advanced civilization wouldn't be interested in running one.
(OR we won't become an advanced post-human civilization ourselves;
though that wouldn't prevent other species from running one).
Apparently too many people dismiss the second possibility and forget reporting about it when discussing the topic.
Also, the paper both assumes that galactic-wide computing power is physically possible, and that computing power is all it takes to generate civilization-deep simulations. I can think of several limits of physics and complexity that could make either hypothesis less than plausible, or at the very least, make option two (the post-humans not being interested in running such simulations) as likely as the "we're in a simulation" one.
>Apparently too many people dismiss the second possibility and forget reporting about it when discussing the topic.
I doubt most people even HN types have read the actual argument.
> I can think of several limits of physics and complexity that could make either hypothesis less than plausible
No one is saying this is feasible in the short term and no offense but I highly doubt that you are privy to the physics available to humans hundreds or thousands of years in the future.
I doubt the limits of physics themselves will change in the future :-P
There might be more knowledge on how to work around those limits to achieve efficiency closer to the theoretical limits. But to assume that a future civilization will have access to nearly infinite computing power (to the point of not caring about throwing several world-computers to a simulation side-problem), well, that's magical thinking.
I'm not saying that it can't happen. I'm saying that it's not the most likely possibility given our current understanding of how the universe works (which while not perfect, is quite a lot).
It all boils down to the first step in your version of the argument: if simulations are improving fast now, they will keep improving forever and reach any arbitrary level of power given enough time. It's the fallacy of infinite growth, ignoring the likely possibility of the growth process meeting some inner limits that will make it end.
I think you are seriously overestimating our current understanding of the universe/physics. For instance we don't even know if our universe is finite or not, if it's infinite then your point is moot and you literally would have access to infinite compute.
I disagree, I have seen research indicating that it's reasonable to have a computing system with on the order of 10^69 bits. There doesn't seem to be anything magical about this thinking at all.
https://arxiv.org/pdf/1705.03394.pdf
By the same argument the people in the outer universe are in a simulation of the outer-outer universe and the people in the outer-outer universe are simulations in the outer-outer-outer universe, etc to infinity.
In other words the theory requires infinite complexity.
1) (Assume that) we can create a simulation with intelligent beings in it.
2) Therefore, it is not impossible that someone has created a simulation in which we are the simulated intelligent beings.
3) Therefore, it is highly likely that we live in a simulation.
I simply don't get the logical implication between 2 and 3 from "not impossible" to "highly likely". I have the same concerns with the ontological argument for the existence of God:
1) I can imagine a being that is perfect and all-powerful.
2) This being therefore exists, because if it didn't it wouldn't be perfect nor all-powerful.
In both cases I see an extreme case of begging the question.