The Vong actually illustrate a real problem with the Star Wars EU. They let the Jedi and New Republic triumph so quickly and easily over the Imperial Remnant warlords that they had to invent new and worse threats out of thin air to keep the series going. Instead of leaning into history and having the galaxy move into a multi-polar era like the Warring States Era or the Crisis of the Third Century they came up with this. You could have had a lot more interesting stories with several persistent Imperial Remnant states that diverged from each other. Like the Pentastar Alignment becoming a hybrid of the CIS and the Empire and Zsinj's empire becoming a hybrid of the Empire, Mandalorians and the crime cartels. But no, we got this crap because the writers couldn't let any Imperial warlord inflict meaningful defeats on the New Republic and force them into a defensive stalemate.