[fnrslvr]

There's a lot of subjectivity to the "we can simulate the universe" variety of claim stated by the article, but I'd tend to forgive considerations of the scale of the entire universe in that claim. It should be obvious that simulating the trajectory of every last particle is straight up impossible. (Even in principle: you could probably even show outright impossibility on logical grounds with a diagonal argument a la the time hierarchy theorem.)

Instead I'd take it as meaning something like, "any slice of physical phenomena there is to observe in the universe, we can simulate given reasonable resources to do so." So, put an imaginary box around some reasonably isolated plot of reality, pick your precision and your time scale, and you could replicate what happens in that space with a "reasonable" computational resource overhead. That's what elevates the quantum simulation overhead objection to number 1 in my mind.