Revelation may well have been compiled into a single book towards the end of the 1st century, but there is plenty of evidence that the visions of John ocurred much earlier and the other apostolic writers were well aware of them much before 60 CE.
There is an estimation that Jerusalem had a resident population of 60.000 people by 66 CE.
Something else to consider: People have assumed that, by riding the beast, the Harlot is in control of the beast. But that isn't necessarily the case. It may also mean that is vicariously living on its back and the beast finally acts to get rid of the troublesome parasitic passenger. Her "kingdom" over the Kings of the earth isn't political, it's spiritual.
Eden