I want to address the absurdity of thinking Isaiah 13 has already been fulfilled.
It's most annoying when I see people who think Isaiah's prophecies are about the fall to Cyrus, where no Battle even happened, nothing happened in the 530s BC that can remotely fit any Bible passages about Babylon besides Daniel who wrote about that history contemporary with it. And defending the accuracy of Daniel on this is something I have done and may continue to do in other posts on this blog.
The informed intelligent people arguing for a Preterist interpretation of Isaiah's Prophecies about Babylon focus on the earlier destruction the city faced in Isaiah's own time, during the reign of Merodach-Baladan.
I indeed do think Isaiah 21 is about that piece of Babylonian History. Chris White makes an argument for that, starting about 8 or 9 minutes into that podcast. He expresses plenty else here I don't agree with concerning the 7 heads and so forth, and I've addressed his own Mystery Babylon view elsewhere.
The problem with applying any of these purely military falls of Babylon to Isaiah 13-14 or Jeremiah 50-51 is that while those include many military and political aspects, ultimately they are also divine Judgments comparable to what happened to Sodom and Gomorrah.
Isaiah 13 includes a statement that the Sun, Moon and Stars will not give their light. That did not happen in the days of Merodach-Baladan, or Belshazzar. But it fits Isaiah 13 being the same as Revelation 17-18 since the effect of the Fifth Bowl of God's Wrath (Revelation 16) will probably not have been undone yet.
And I've talked about Isaiah 14 and the Fall of Lucifer extensively elsewhere, that happens in Revelation 12, at the midway point of the final Seven year period.
There is not a near and far fulfillment issue here, Isaiah 13 does not perfectly or even vaguely fit any past events. All anyone can do is say "hey look, Babylon fell, that must be what Isaiah meant" but an analysis of the details will never hold up.
And for all the "there are no modern Medes" nonsense, I have earlier posts on the Medes and the Kurds. But in Isaiah 21 the Medes (and Elam) are on Babylon's side, not enemies as they are in other prophecies.
People who want to make Isaiah 21 about the fall to Cyrus in addition to ignoring that the Medes are Babylon's ally here, want to make Elam a reference to Persia. The Persians were not the same people as Elam, in fact the Persians were probably Japhetic like the Medes were, they may even be Medes themselves once traced all the way back to Genesis 10.
As far as Isaiah's additional Babylon references in chapters 43, 47 and 48. Well I haven't delved into those too deeply yet.