Gere some adittional info belllow about basemap function,

The base map is necessary for basic navigation appropriate to represent where you are located and to see the boundaries of countries (the approach to them or removing scale to the size of the earth ball ).For routing , it is not necessary. It doesn't have some real practical function, but where is no map of some country, and we drive near to that country, and no borders , without basemap in this case we'll see only a great big white spot, but if we use basemap, then we can see at least an approximation to the borders of countries that are not in contact with country through we driver.

However, not bad to have it in map folder, my suggestion leave it there.