“Musk’s Matrix-style simulation hypothesis comes from the fact that the Universe has been around 13.8 billion years, and in that vast period of time he says it’s statistically likely a civilisation has figured out how to make a fully believable simulation.”
If we’re in a simulation, then we have no idea how long the actual universe has been around, and no way of determining that, thus we would have no evidence for how statistically likely any of this would actually be...
There is no actual universe and the simulation of it isn't really a real simulation either.
It's more like a dream, dood!