The Ballad of Songbirds and Snakes provided a deeper look into the psyche of Coriolanus Snow, the president of Panem during the original Hunger Games films. It showed exactly how he grew from a young boy from a struggling family into the tyrant audiences were familiar with. Not only that, but it provided a valuable insight into the culture of Panem and the origin of the Games themselves, which only makes the initial entries to the franchise that much more distressing. It does everything a prequel should do: tell a unique story while maintaining the familiarity of that which came before.
Source：https://www.cbr.com/the-ballad-of-songbirds-and-snakes-sejanus-plinth-explained/
