You're too fixated on that one verse. There are other verses that describe Babylon in other respects to show that it isn't Jerusalem.
So if Jerusalem is destroyed and never found, where will the Lord Jesus reign when He comes back? You never answered that.
First of all, neither you, nor I, nor anybody else should ignore any of the descriptors that we are given of this "great city" in the book of Revelation, but that is precisely what you and several others here have foolishly chosen to do. Like it or not, this "great city" is guilty of the blood of prophets, and the Bible (Do you believe the Bible?) places that blame upon one city, and upon one city alone:
Jerusalem.
If that rubs you the wrong way, then too bad. It is the word of God, and neither you nor anybody else here will ever prevail against it.
Also, I have covered several other descriptors of this "great city" which equally point directly to Jerusalem, so, no, I am not fixated merely upon that one verse, but, unlike you, I will not ignore it.
Finally, I did already properly answer this question that you again posed.
Like I correctly said, a comparison (Do you know what a comparison is?) was being made there between "Babylon the great" and literal Bablyon.
Here is the text, again:
Jeremiah 51:60-64
"So Jeremiah wrote in a book all the evil that should come upon Babylon, even all these words that are written against Babylon. And Jeremiah said to Seraiah, When thou comest to Babylon, and shalt see, and shalt read all these words; Then shalt thou say, O LORD, thou hast spoken against this place, to cut it off, that none shall remain in it, neither man nor beast, but that it shall be desolate for ever. And it shall be, when thou hast made an end of reading this book, that thou shalt bind a stone to it, and cast it into the midst of Euphrates: And thou shalt say, Thus shall Babylon sink, and shall not rise from the evil that I will bring upon her: and they shall be weary. Thus far are the words of Jeremiah."
Compared to:
Revelation 18:20-21
"Rejoice over her, thou heaven, and ye holy apostles and prophets; for God hath avenged you on her. And a mighty angel took up a stone like a great millstone, and cast it into the sea, saying, Thus with violence shall that great city Babylon be thrown down, and shall be found no more at all."
Now, I am going to ask you a very simple question, and let's see if you can answer it honestly or not:
Has literal Babylon, which "that great city Babylon" is being compared to here, ceased to exist?
Of course, the correct answer to this question is "NO!"...and the same will apply to "that great city Babylon" which is here being compared to her.
Also, do not miss the part where God avenges the prophets on "that great city Babylon."
Again, whether you like it or not, God can only avenge the prophets upon those who have killed the prophets, and that is "the great city" of Jerusalem.
Now, will you kick against these biblical truths again, or will you repent and embrace the same?