At first I assumed literally everything in Eorzea is destroyed, or at least most all of the cities. However, looking at the video again, if this was actually the case, then how are the archons praying at the shrines inside the city? This is shown after the initial destructive volleys into the city. It's reasonable to believe that they might have been hit by more after we're shown them praying, but for the most part it seems the major cities aren't completely destroyed, just severely damaged. This is directed at those, to who I shared common sentiments, that believed we had to be warped to a different dimension as well as time as there is no possible to way to completely rebuild cities that large in 5 years.