Babylon certainly received a judgement in 539 with its Fall but Jeremiah focussed on a more permanent judgement, one of desolation foretold from Jer.25: 12 onwards.
Wrong again scholar!
Jeremiah's focus concerning the 70 years was that those 70 years would be the period that Babylon would be a world power and during such time the nations would have to serve Babylon as such. Serving Babylon was not dependent on being in captivity or desolate. The serving started as a result of Babylon becoming a world power and it ended when their time as such a power ended.
[Jeremiah 25: 11 And all this land will be reduced to ruins and will become an object of horror, and THESE NATIONS will have to serve the king of Babylon for 70 years.”’ 12 ‘But when 70 years have been fulfilled, I will call to account the king of Babylon and that nation for their error,’ declares Jehovah,]
[Pay Attention to Daniel’s Prophecy! – The Great Timekeeper, Jehovah, had numbered the days of Babylon’s reign as a world power, and the end was closer than anyone at Belshazzar’s banquet thought.]
[Daniel 5:26 “This is the interpretation of the words: MEʹNE, God has numbered the days of your kingdom and brought it to an end.]
[Isaiah’s Prophecy 1 p. 253-254 par. 21 – Evidently, the 70 years represents the period of Babylonia’s greatest domination]
[Jeremiah 27:6 And now I have given all these lands into the hand of my servant King Neb·u·chad·nezʹzar of Babylon; even the wild beasts of the field I have given him to serve him. 7 ALL THE NATIONS WILL HAVE TO SERVE him and his son and his grandson until the time for his own land comes,’8 ‘If any nation or kingdom refuses to serve King Neb·u·chad·nezʹzar of Babylon and refuses to put its neck under the yoke of the king of Babylon, I will punish that nation with the sword, with famine, and with pestilence,’ declares Jehovah, ‘until I have finished them off by his hand.’9 Therefore, do not listen to your prophets, your diviners, your dreamers, your magicians, and your sorcerers, who are saying to you: “You will not serve the king of Babylon.” 10 For they are prophesying lies to you, so that you will be taken far away from your land and I will disperse you and you will perish.11 ‘But the nation that brings its neck under the yoke of the king of Babylon and serves him, I will allow to remain on its land,’ declares Jehovah, ‘to cultivate it and dwell in it.]