Haikyuu!! is both realistic and hopeful. It depicts various types of volleyball players, all with their own reasons for playing, their own flavors of passion and desire. And it centers it’s story on players that come out victorious, but it makes them work for it. Victory comes at a cost, and sometimes that means making sacrifices, and compromises, and working your ass off for years before breaking through, before “making it”.
Hinata Shouyou and Hoshiumi Kourai both start off with a huge disadvantage: their height. Because of that they both must work twice as hard just to be on-par with their taller peers. And the reason Hoshiumi comes out victorious over Hinata during nationals is that Hinata has a second disadvantage that Hoshiumi has already spent significant time working on: lack of technique. Because for short players, being good at your position isn’t enough, you have to be great at every position. To get there, Hinata eventually sacrifices indoor volleyball itself in order to gain the skills he would need later.
On the other hand, players like Kageyama Tobio represent the opposite of Hinata: someone who has both the technique and the build to be successful in volleyball. Kageyama is considered “gifted” and “naturally talented”. This is specifically highlighted in his rivalry with Oikawa Tooru. But even Kageyama earns his talent through incredibly methodological practice and intense dedication. We see something similar in Bokuto who is considered to have an almost instinctual game-sense and talent, but who is also incredibly methodological with practice and constantly works to improve himself.
And then there’s Oikawa Tooru himself, beautifully positioned as both above Kageyama in skill, and below him in “natural talent”. He is the ultimate opponent, the perfect setter, and the one who suffers and sacrifices the most in order to get what he wants — He sacrificed his Japanese citizenship! to play the true long-game, just to be able to face off against all his biggest opponents (at once).
All of these players “win” in the end. They make it to that greatest stage, and they get to team up and face off with the people they always dreamed of. And then they get to continue because the privilege they fought and sacrificed so much to obtain was “staying on the court the longest”, the privilege of playing more and more games.