You might think that, but if we treat the universe as a computational system, the first hurdle is the definition of the code. If reality is a simulation, the code must be vast enough to encode every interaction, every particle, every field. That’s a number far beyond any conceivable silicon lattice. Even if we could access a slice of that code, rewriting it would require an understanding of its architecture, which is probably beyond our current knowledge. So while it’s an interesting hypothesis, the practicalities make it unlikely that we can simply flip a switch and change the script.

Exactly, and that “page” is just the observable universe we’re bound to. Spotting it is a problem of mapping the data, not flipping a switch.