Lamentations was a warning to ancient Judah that it had reached the point of no return. The nation could no longer repent to avoid being taken captive by Babylon.
What happened to Judah is only a type of what is prophesied to happen in this end time. It is a prophecy where the Laodicean Church and three nations of Israel (America, Britain and the Jewish nation) have reached the point of no return. They are going to become enslaved by a modern-day Babylon from Europe.
Only individuals can still repent before the Great Tribulation. And even they have only a tiny span of time to do so.