playing against hinata has never been about winning or beating him or hindering him at becoming better for kageyama. he always wanted to stay on court longer, which naturally happens when you're good- because you end up playing against others that too are good. +

for that he found hinata, as a partner, but also as a rival. with hinata as a partner he can preserve against stronger opponents and stay on court longer and with hinata as an opponent he HAS a strong opponent that can guarantee him to deliver a long and fulfilled game +

the same goes for hinata too. their goals align, which is why they work so well together. they want the same thing: to get to play more volleyball. hinata saying this to kageyama is but a promise to become someone stronger, reflecting kazuyo's promise to kageyama as a child +

to kageyama that promise doesn't mean he has to start pushing against hinata, because he's afraid he's gonna beat him. kageyama doesn't care if hinata beats him, moreso it's just proof that he's finally found someone stronger and gets to stay on court longer, that's what he wants

kageyama and hinata might be rivals, might be opponents, but they were never antagonistic to one another. they always represented the fulfillment, but never the hindrance of their goals, because their goals are intertwined. +