All these "world as a simulation" models assume that the ones doing the simulating are 1) in "our" future (if that even makes sense), and 2) like us. It would make much more sense to assume that they are not like us and exist in a dimension we cannot possibly imagine. In effect, the question "is our universe a simulation?" is the exact same question as the age old "is there an all powerful god?" And the same logic could be used to prove there's an invisible killer robot from the future living in my cupboard.