It's hard enough to achieve that in any game unless you put the player on rails. Even games the size of a city tend to have massive immersion breaking compromis

It's hard enough to achieve that in any game unless you put the player on rails. Even games the size of a city tend to have massive immersion breaking compromises (look at any Bathesda game, Cyberpunk, etc.) Now try scaling that to a whole non-procgen universe!