Right at the very end of the tribulation, Babylon comes in remembrance before God, to give her the cup of his wrath:

Revelation 16:16 And he gathered them together into a place called in the Hebrew tongue Armageddon.

  17 And the seventh angel poured out his vial into the air; and there came a great voice out of the temple of heaven, from the throne, saying, It is done.

  18 And there were voices, and thunders, and lightnings; and there was a great earthquake, such as was not since men were upon the earth, so mighty an earthquake, and so great.

  19 And the great city was divided into three parts, and the cities of the nations fell: and great Babylon came in remembrance before God, to give unto her the cup of the wine of the fierceness of his wrath.

Then, two chapters later, as she receives that cup of his wrath, it says:

Revelation 18:7 How much she hath glorified herself, and lived deliciously, so much torment and sorrow give her: for she saith in her heart, I sit a queen, and am no widow, and shall see no sorrow.

  9 And the kings of the earth, who have committed fornication and lived deliciously with her, shall bewail her, and lament for her, when they shall see the smoke of her burning,

  11 And the merchants of the earth shall weep and mourn over her; for no man buyeth their merchandise any more:

  17 For in one hour so great riches is come to nought. And every shipmaster, and all the company in ships, and sailors, and as many as trade by sea, stood afar off,

  18 And cried when they saw the smoke of her burning, saying, What city is like unto this great city!

It appears that up until that moment she had been living deliciously, and that she had not seen sorrow, and didn't expect to.

Also, that the kings of the earth had been living deliciously with her.

And that the merchants of the earth had been selling to her up to that point.

Also, all the company in ships, sailors, and as many as trade by sea were seeing her burn.

My question is regarding the teaching that all the seals, trumpets, and vial judgments are universal and worldwide,

that over half the world is dead, the world's vegetation destroyed, all the oceans are like the blood of a dead man,

that the whole world is still in pain from the vial where they were all scorched with fire, the world's economy is destroyed,

then how could Babylon still be living deliciously with the kings of the earth,

and then how could all thee people still be trading with her, if the whole world is practically destroyed before this?

The follow up question is whether the seals, trumpets, and vials may be localized?

Could the sea spoken of, be actually like it says, a sea, singular?

It seems to me, that localized plagues, like in the book of Exodus, make the reading of chapter 18 more understandable.

Am I really wrong about this?