It could also be due to a new mission or purpose that he discovers which is not in line with Team 7's goals. If there is a greater threat to the ninja world that requires his 'godlike' abilities and can only be achieved alone or with a different group, he may choose to leave Team 7 to pursue it.
One possible reason could be a sense of being too powerful and outgrowing the team. If Naruto in the fanfiction has become 'godlike', he might feel that the training and missions of Team 7 are no longer challenging enough for him. He may seek greater challenges elsewhere.
Chapter 9, "Ice Shuo, Vermilion Frost, Gold Lin", is the clearest early answer because it turns Gold Frost Tree's situation into a concrete plot event. The chapter turns that into something concrete by moving from The Great Xia Camp has finally birthed a new logging-grade combat... to The inner trees were more terrifying, with diameters of five or six....
Chapter 143, "Picking Up a Bargain, Acting Maliciously [Three-in-One Mega Chapter]", is the clearest early answer because it turns Cold Beasts's situation into a concrete plot event. It opens with The tacit understanding cultivated over a long time allowed everyone... and closes on Moreover, once it was trapped, it couldn't pull itself out....
Chapter 3, ", Indistinguishable Truth from Falsehood [Please follow and rate!]", is the clearest early answer because the hidden truth stops feeling like mere subtext. The chapter turns that into something concrete by moving from What's happening?" Xia Hong couldn't help but feel deeply anxious at... to If the entrance remains open, even if they luckily withstand the low.... What makes it stick is that the chapter closes with PS: Can you tell which one is real and which is fake?
Chapter 506, "Let Them Come", is the clearest early answer because it turns Damien's situation into a concrete plot event. The setup is And then it was replaced with something else., but the pressure keeps building through He felt the stone behind him.. Once the chapter lands on They didn't make it ten meters., the chapter closes with The hunt was far from over., which gives trade and resources a stronger narrative position and pushes the power growth onward.
Chapter 16, "First Collision", is the clearest early answer because it turns Cold Beasts's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Leader, I've made a breakthrough." "Brother, I've also reached the... and follows through with I'll go back and notify Father to come with reinforcements right....
Chapter 138, "The Bizarre Mirror Immortal Gu, Cold Resistance Level? [3 in 1]", is the clearest early answer because Yuwen Hu finally turns buildup into a real advancement. The chapter turns that into something concrete by moving from Mirror Immortal Camp, inside a wooden house next to the bamboo... to After a reproachful remark, he saw the Cold Beast Blood and brush on....
Chapter 45, "My name is Xia Hong, the Great Xia Leader [Here He Comes]", is the clearest early answer because it turns Shi Qing's situation into a concrete plot event. It opens with As soon as night fell on the second day, Shi Qing went to find Luo... and closes on Even Rogel Camp couldn't possibly have five Loggers so young..
Chapter 138, "Mirror Immortal Strange, Cold Resistance Level? [3-in-1]", is the clearest early answer because Deceitful Monster finally turns buildup into a real advancement. The chapter turns that into something concrete by moving from When we just merged, the temperaments of the brothers He Meng and He... to When everyone in the camp truly accepts the Mirror Immortal, even....
Chapter 141, "Intermediate Thunder Kui, Second Reshaping Skin [Three in One]", is the clearest early answer because it turns Snow Mane's situation into a concrete plot event. The chapter gives readers a real answer by opening on Not only that, but above the Ice Tree, lightning occasionally... and ending on Unexpectedly, we encountered an Intermediate one before even hunting.... In story terms, the chapter closes with The swamp beside the tree was likely the Thunder Kui's habitat.
Chapter 480, "New Variants", is the clearest early answer because it turns Damien's situation into a concrete plot event. The setup is There was no dramatic punch, no drawn-out conflict., but the pressure keeps building through Damien simply twisted, grabbed the mercenary by the collar, and....