The TL;DR: Scientists have created an absolute computational monster of a Universe digital twin simulation.
Such sophisticated models, simulations and predictive tools are measured by the material and organisational costs as displacement of complexity into integrated hardware, processing and memory as much as by the representational and referential eloquence or associated, inductive insights they may invoke.
The core principle that might not be entirely obvious at first or cursory glance is that of a hyper-inflating and exponentially accelerating representational technological system that in microcosm mirrors back as reference, not only the instances as artefacts and entities, but the global systems properties of a recursive material and information-processing (i.e. computational) complexity of a Cosmos it seeks to mirror but that forever reflects itself, as itself in life, intelligence and technology.
Recalls something Jorge Luis Borges wrote about maps approximating to exact overlays of the territory they represent; the most accurate simulation of a system being that system itself. Could we use the Universe to simulate itself at scale? Does the Universe already do this? Do we just not notice that technological evolution is a microcosm of this?
We and all our technologies are component parts of a Universe that simulates itself, through and as us. The greatest question here might be as to whether or not we are simulating what is of actual significance or only what we are able to simulate. We seem on the whole to be quite enamoured of instances as artefacts and entities or teleologically reflexive endpoints and nodal pivots of conceptual leverage but as a consequence often entirely miss the underlying principles that those instances embody.
The effervescent sociotechnical abstractions of representational Cosmological microcosm in and as abstract self-simulation being an instance of a class of much larger philosophical questions here.