It reaches a dead end eventually. That's where we are, edge of speed, where the only mods left are aesthetics veering at photorealism.

The game simulation will get more detailed/granular as aesthetics dial down in perceived value. You can always go bigger/wider/more procedural/more multiplayer.

This is also why every hard problem eventually shows up — games are just simulation + interaction, and eventually everything that can be simulated will have some attempted implementation out there, struggling along. (For some reason, this does not appear to stop at “interesting” things to simulate — see all the literal simulators on steam)

The simulations have yet to release photo-realism in lieu of event-perception, where simulation parallels reality, but that's not really playable as a game, only as a view.