This goes back to my thought on compressibility. The article's argument is built on the assumption that some data in the universe can be ignored and the whole c

This goes back to my thought on compressibility. The article's argument is built on the assumption that some data in the universe can be ignored and the whole computation made more efficient. It's not a trivial assumption. I actually lean towards an incompressible universe, intuitively. If the universe is incompressible, then you may only ignore parts of the data for a finite time. For example, arranging an illusion of the night sky might have taken no computation before astronomy, but as we record the positions of celestial bodies and understand the laws governing them, the computations have to be run retroactively since the big bang. Otherwise the simulation would be inconsistent. So the question is what can you remove from the causal chain from the big bang to this moment? If you think some things are removable, you have to prove that something exists in the universe but does not touch any causal chain humans (or perceivers) may wish to investigate at any point in the future. If nothing is removable, then you cannot choose to not simulate any part of reality based on perception, because whatever you don't simulate may eventually need to be simulated.