Chapter 18 is in the midst of the chapters that focus on the perspective of a woman name Babylon. Although her name is associated with the city that the Israelites were once exiled in, she represents all of the seductive aspects of life throughout history. In one of the longest chapters in Revelation, it is made clear that even the things which we and our society value the most will be reduced to ashes.
Yesterday's chapter ended with the kings of the earth, who had been under the spell of Babylon, assert their desire for total control and authority by killing Babylon.
However, Once the allurement brought about by human greed is destroyed, the rest of society (vs. 9-20) crumbles away. All of the treasures and desires that seem so tempting now drive so much of the work we do as a society, and when the treasures go away, everything else seems to fall down with it (vs. 21-24).
THE HYMN OF DEFEAT: Three separate groups sing a song to mourn the loss of what had been the center of their livelihoods: The kings (v9-10) who ruled over the luxuries, the merchants (v11-17) who made fortunes by selling Babylon's luxuries, and the sea captains (v17b-19) who transported the luxuries. Notice the similarities of the songs they sing, and how the song gets progressively longer each time it's sung, and how each song ends with the same line:
In one hour her doom has come / she has been brought to ruin (v10, 17, 19)