Add in things like character customization, pets, multiple endings, a day and night cycle and weather and you have yourself a hot pot of resource management to contend with. For open-world games there may be event triggers but they may or may not go off depending on where the player goes or what they do.
Most times triggered events are placed along a set path a little like explosions rigged to go off at a certain point in a Hollywood movie. In corridor shooters or racing games the only reactive variables are the AI or maybe some set pieces being destroyed. Open-world games are especially taxing on consoles because they have to constantly adjust for a lot of unpredictable things that players may do to change the way the game world reacts.
