There is future tech and hover planes in the world of The Hunger Games, but what really makes it sci-fi is the aspect of sociology involved, which is the crux of most dystopian fiction.
The Hunger Games makes for great sci-fi because it revitalizes those ideas, and connects them to the entertainment industry that we have today.
I’m not saying that it could ever happen, but I’m also not saying that it can’t happen, either.
Here is a society that has been pushed so far apart economically that murdering the poor has officially become a sport.