If we're a simulation or indeed some kind of subjective world, then the rules of physics are also an illusion. So I'm not an anti-realist in looking at it that way. But here's another way of approaching it, which is to say that the objectivist fiction and subjectivist descriptions like the mythopoetic or some a priori philosophical approaches are like two rails that the train rests on. The fact that it's subjective doesn't mean it's just arbitrary or chaos or all illusion.