Nick Bostrom & Ludwig Wittgenstein
From a Wittgensteinian standpoint there's no essence to either illusions/simulations or reality that could aid us in telling them apart. — Agent Smith
Actually, there is an "essence" underlying perceived reality : I call it "Information". Unfortunately, materialist scientists have ruthlessly dissected reality looking for its fundamental substance. The problem is that they imagined that substance as tiny balls of hard stuff. But eventually, Quantum researchers have been mystified to find that the foundation of material reality is mushy Mathematics (Fields of intangible potential ; invisible WaveForms ; mind-stuff). Their "substance" is essentially the Information necessary to describe the statistical probability of their physical existence at a particular place & time. So, it seems that Reality is based on illusory gambler's odds.
The current issue of Philosophy Now magazine (149) has an article that mentions Bostrom's "simulation hypothesis". His issue is to know whether there is "a mind-independent reality". And Nozick's similar Experience Machine thought-experiment concluded that a convincing simulation of Reality would "prevent us from grasping any deeper reality". So it seems that, for all practical purposes, Reality is what you experience : the information you take-into your mind, from which to build a model of the source of those incoming bits of experience. However, speaking for most of us, Nozick said, "we want to have a genuine relationship with reality, not live a fictional life that only feels real". (a la Matrix). "This means that for many people there must be something --- perhaps reality itself -- that is valuable in addition to the feels of experience".
I suppose it's that feeling of incompleteness & imperfection in the perceived world, that caused ancient philosophers (e.g. Plato) to propose an Ideal World, of which our mundane Reality is merely a simulation. Perhaps, the felt need for "something more" is what allows the majority of people to imagine (and believe) in super-gods & heavenly homes, where Reality is closer to Ideality. So, how can we tell them apart : the mind-model of Reality from the unknown real-Reality? Does it really make any difference? Obviously, some people feel strongly that it does. Which is why Morpheus, and his crew, chose to live in a hadean underworld, instead of the "normal" matrix simulation. If only we-in-the-normal-world had magic pills, so we could tell them apart.