Our meatspace universe has billions if not more galaxies floating around in space. To try to replicate that manually for a realistic VR space travel experience would clearly be a nightmare task. But if the galaxies and planets could be procedurally generated over time depending where the avatars were at a certain point you could create some fascinating experiences.
Procedurally generated forests and deserts could help create more open adventure games. Human game designers shouldn’t feel the need to create every tree a user passes by.
Procedurally generated horror games could gather data from eye / face tracking, as well as heart monitoring, to build more uniquely terrifying experiences geared to the specific user. Somewhat like what happens in Black Mirror’s Playtest episode.
These kinds of computations can help create a sense of natural change as well. That plot of land you leveled a year ago might have some procedurally generated weeds growing in it.
VR is a fantastic space to more accurately reflect the human imagination, but not everything created in VR has to come directly from human minds and hands.