Vietnam never went through its obligatory purge of capitalist elements and instead just subsumed the garbage from the south that they captured from Americans, combining it with dead end brezhnev communist thinking.
The north, representing the areas where China had historical influence and where the CPV was started, are the better developed and far less mentally degenerated part of the country. While the south, and worst of all, the compradors that escaped to the US after America lost, represent the colonial bootlickers.
Vietnam would have benefitted from a cultural revolution that would have swept away the compradors. But they didn't have the foresight to do so, and now the good and the bad parts of the country is suffering from stagnation.