[jfabre]

Well for starter it saves the state of the maps.

You never build anything too crazy in real life, because it requires a lot of setup during and between games. It's just not worth it.

In digital form, you can afford to prepare big 3d maps outside of the game, and you can even share the environment you've created with other people outside your game so that they use it in their own game.

After playing for a couple of sessions though, I don't think having huge maps is worth it (yet?). Just a map of the building you're in, in 3D is good enough and makes it easy for the players to imagine a city or town around and not lose track of where everyone is.