I think the early part of the series did an okay job of establishing that Sasuke is a Batman-style "my parents are dead" brooding edgelord, while Naruto is an annoying loser. Naruto hates Sasuke for being much cooler than him, while Sasuke hates everyone, with Naruto being particularly annoying due to the obvious shots he takes at Sasuke.
Placed on the same team, they fight with each other, they become rivals, and they slowly develop a kind of friendship with each other. IIRC, there was at least one point in the Zabuza fight where Sasuke selflessly took a hit for Naruto, even though that was strategically a bad move. Naruto similarly softened on Sasuke, even though they remained rivals.
But then Itachi showed up in the Leaf Village and humiliated Sasuke, and reminded him that his parents were dead, and made Sasuke think "WTF am I doing playing around with being friends with these people and trying to be happy? I'm supposed to hate everyone" which turned Sasuke against his team and made him join Orochimaru, as he was convinced that evil was a faster route to getting stronger.
For both Sasuke and Naruto, their friendship (such as it was) was the first friendship they had ever experienced. Sasuke decided to throw that away, Naruto refused. Bearing in mind that Naruto's "ninja way" is that he will never back down, never surrender, and that when Sasuke first left, Naruto foolishly promised to Sakura that he would bring Sasuke back and force him to change his mind. It's pretty ridiculous that Naruto stuck to that stubbornness for so many years, and it should've destroyed Naruto's naivete when he failed to stop Sasuke from leaving.