They provide perspectives that cannot be gained any other way. Even if you had instant access to a helicopter or airplane or even a prominent mountain, you would still be unable to get the perspective you can get by looking at a map, or a series of maps. Use them a bit. They've come in handy a time or two. Not at all.
Maps are more than just pretty pictures with some geographic names.
Take a topographical map, for example. Especially one overlaid with political boundaries. The boundary lines will help you identify the overall regions where your ancestors lived, but the topographical detail will show you how they would have travelled. Whether they would have been able to follow a more or less straight path, or if the road would have wound around mountains and other obstacles. Whether they would have been forced to travel overland, or whether a river or canal would have been more convenient.