In a building with just three rooms, the rooms can communicate directly with each other, with doors placed on the common walls.
Once you add a fourth room, you will need a hallway in between in order to go from each of those rooms to the other three rooms.
This is a law of architecture, and since most homes have at least six rooms (living/family room, dining room, kitchen and three bedrooms) hallways are a necessity.
Hallways are also bad Feng Shui.
Many modern home designs hide hallways within living spaces so that circulation happens through rooms instead of on dedicated hallways surrounded by walls.
When you do have an identifiable hallway in the home, it always comes with problems, and it always needs to be “cured.”
Hallways represent communication. They also symbolize the connections between the areas of life represented by every room.
When hallways are not handled well, the chances for arguments increase.