The title and the article are both independently true, just not together :) As in, there are certainly cosmic simulations that once needed supercomputers which now run on a laptop, that's just the story of computational progress.

More seriously though, https://www.404media.co/a-vast-cosmic-web-connects-the-unive... is another nice article about this work. It has a bit less detail (i.e. less proper nouns in it), but is more readable for it IMO.