It would be meaningless, if we lived in an undetectable simulation. But IIRC, there's a recent paper that allows us to detect if we live at least in certain kinds of simulations.
If I understand it correctly, they basically say "Our universe is discrete, therefore we're in a simulation".
Ok, if "being in simulation" == "discreteness", than yes, "being in simulation" is meaningful. But why not just argue whether our universe is discrete? Why introduce the concept of simulation, which evokes a picture of some higher level universe with a big computer running our universe. Which is just an idea in our heads, nothing more.
"We're in a simulation" implies that our universe is discrete, nothing more, so it's meaningless in a sense.
(Other problem is that if we're in a non-discrete universe, we may be able to make non-discrete software. But that's not the main point of what I tried to say.)
Only if we assume that the "host" universe's computers are discrete, an assumption for which there is exactly no basis. We can't even speculate about the physical laws of the outer universe, much less what kind of computers it has, if "computers" as we know them even a valid concept.
Nitpick: "We are in a perfect and undetectable simulation" is a meaningless statement. If e.g. someone found a privilege escalation in our reality's VM that would be quite meaningful.
I get what you are saying, but I disagree. If there were millions of invisible unicorns, surely we'd occassionally bump in to one. Azaleas would go missing. With the right technology, it might be possible to harvest them for ivory or meat or hoofs for glue.
If we live in a simulation, there may be experiments that would demonstrate the fact. There may be ways to 'hack' the simulation and break all kinds of physical laws.
By "invisible unicorn" I meant a unicorn that doesn't have any effect on the physical world.
Our universe could behave, in some ways, like a computer simulation (but the question is, in what specific ways?). But it is similar to light rays behaving like waves. Which is different from light rays being equivalent to waves.
