WARNING: The following contains spoilers for Haikyu!! Season 4 now streaming on Crunchyroll, Funimation and Netflix.
In the world of Haikyu!!, Shoyo Hinata is the star of the show. After working hard to get better at volleyball, despite his short stature, Hinata is eventually accepted at Karasuno High School and makes it into the volleyball club. There, he reunites with a foe from the court -- Tobio Kageyama. As they butt heads, they quickly bond with their other teammates and grow and develop their skills. Even though he's quite short, Hinata is determined to be an amazing spiker, like Karasuno's Tiny Giant before him. Kageyama is an infamous setter in the prefecture due to his incredible skill level.
Although they're in constant competition with one another and seem consistently at odds, Hinata is pretty dependant on Kageyama. Because Hinata has spent so much time focused on his spiking skills, his general volleyball skills like receiving or serving are lacking. However, when Kageyama is able to successfully set to him, Hinata's skills shine through and he's able to land incredible spikes insanely fast.
But is Hinata really doomed to fail without Kageyama by his side? In Season 4, Hinata crashes a training camp to which his fellow teammate Kei Tsukishima was invited. Forced to watch on the sidelines as the ball boy, Hinata observes some incredibly strong volleyball players from his prefecture. He's able to watch how better plays pass, receive, set, spike and serve the ball across the court, and even though he doesn't really get to join in, he sees this opportunity for what it is -- a chance to learn.
Hinata takes these skills forward into his own practice, without Kageyama. Hinata knows, and states on multiple occasions, that his general volleyball skills are lacking, but he consistently works hard to better each aspect of his game. Kageyama is also separated from Hinata in Season 4, as he's invited to take part in the All-Japan Youth Camp. During this time, Hinata and Kageyama develop their skills without the aid of one another.
Although Hinata relies on Kageyama's excellent setting skills to shine during a game, he has an incredible amount of determination that can take him far in volleyball. For now, at the beginning of his career, it's okay to learn the ropes with a talented setter like Kageyama by his side. However, Hinata also consistently exposes himself to new challenges and opponents, always pushing himself to become a better player than the moment before. His skills are still in development, but Hinata has every ounce of potential to become an incredible volleyball player in his own right.
He will always have Kageyama to thank for his start, and as they grow and develop together at Karasuno, their attacks will only become more and more intense. While Hinata will likely outgrow their set/spike setup that they heavily rely on during gameplay, Karasuno's rise from the bottom is mostly due to their powerful combination. So, while Hinata won't necessarily need Kageyama to thrive forever, they definitely still bring out the best in one another on the court.