I think it's hasty to say the story went downhill immediately after the Pain arc majority of the fanbase tends to agree it started going downhill when Madara was immediately destroyed by Naruto and Sasuke after gaining their Sage powers. I might argue the decline started a tad bit earlier given how hyped the sage tools were to be utterly discarded, Suigetsu's plot of gaining all seven swords abandoned, and we hardly got to see the reanimated seven swordsmen fight before they were abruptly sealed. Kaguya was handled well despite most western fans seemingly oblivious to her blatant foreshadowing since Obito was revealed though i absolutely do not think the final fight was handled appropriately whatsoever. Sasuke didn't need to announce his plan to kill the Kaga instead of simply doing so nor do i think it was smart for their final battle to take place after fighting for 3 days straight. Sasuke was handicapped from the start due to lacking the sword he'd been using for three years straight with the fight immediately escalating into Cell Saga power levels. There was an utter lack of finesse,tension, and emotion which was beautifully presented in their first fight. I'm usually on my own here when mention where I started disliking it, but I did noticed that recently, some youtube channels started doing retrospectives about Naruto from start to finish, and I feel like people are realizing that the pain fight was probably the most significant fight for Naruto as a character. Like think about it, pain (nagato) was the leader of the Akatsuki (at least on the surface, even though obito was the really founder and pain was just following his influence, it was clear that pain was the most powerful dude in the show by a somewhat large margin). Pain showed up, fought and killed jiraiya (one of my fav fights), naruto's essential father figure. He came to Konoha, nearly singlehandedly invaded the entire village, killed the majority of the village with little trouble, killed Kakashi too, then preceded to nuke the whole fucking village. Was about to kill tsunade too if Naruto didn't show up. Fought against perfect sage Naruto (who at this point was said to have surpassed jiraiya and the hokage from Kakashi's perspective [and mine too buts that's a different topic about power creep and cliffing]. He defeated Naruto. He then had a talk with Naruto (this is the most important part) where he showed the main protagonist that the world isn't as black and white as he once thought and that Konoha has done terrible acts just like all the other villages. The most pivotal point was when he asked Naruto how he would handle this and Naruto replied "I don't know." People don't realize how important this was as a development for naruto's character. Essentially, pain did a talk no jutsu on the main character and it worked. Naruto, who has always had an answer, albeit, a childish one for every villain, was now speechless and filled with despair. Afterwords, he (apparently) killed hinata, right after she confesses her love for Naruto with him watching on helplessly. Lets take a second to think about all the main characters pain has killed at this point and the damage hes caused. No other villain accomplishes anything near this. In a fit of rage, the kyuubi broke out and took over, the fight escalated to the point of 8 out of 9 tails being released. And the 9th tail was being released (as we saw from yamato's hand) which meant that the seal was finally broken and Naruto was actually going to die as the kyuubi was released for good. Pain was about to make an even chibaku tensei and was going to fight even the kyuubi. So the constant build up since the start of the series about Naruto slowly releasing more and more of the kyuubi's chakra until all of it came out had finally been realized. Right as it happened, Naruto meets his father in the long awaited scene (big fucking deal) and learns what needs to be done while also being reinvigorated to search for an answer to pain's question and jiraiya's life long quest of ending the cycle of hatred. He overcomes his anger and regains control of the kyuubi (obviously because of minato redoing the seal one last time) and fights the final body of pain in a last 1v1 and wins. Then goes and meets the actual body and has a long talk no jutsu with him and turns him. He comes back to the village and is welcomed back (everybody got revived by nagato) as a literal hero for the first time in his life. This is naruto's original goal since the beginning of the series, to be accepted by everyone and looked up to by everybody. And ofc, he was easily the strongest ninja in the village at this point so was able to be hokage (although he was still pretty young so Kakashi was still the first candidate). In other words, the pain fight felt like the most significant point the series for Naruto as a character. I felt really invested in the fight since it just felt like the arc with the most actual consequence. Its something I wish was replicated in the later arcs. Its what I felt was missing. Afterwards is what I call the power creep, although power creep was relatively slow up until the actual war begins, and then it goes on full runaway effect once the fight against madara reaches its peak. There are so many things I would've done differently for the war arc but whatever. At least the series didn't end up like Bleach, even if I hated what the fighting in the series turned into towards the end. I agree, the kaguya shit was hinted at earlier when the sage brought her up in a little mention about his past. The big problem was how madara was handled. I really wasn't a big fan of the sage of six paths shit but since madara was kind of the final villain I let it go. The fact that they trolled him with the whole black zetsu betrayal was pretty ridiculous. I think that pissed off pretty much everybody. What I did hate was the otsutsuki shit. My hunch is that shonen probably came up to kishi maybe around chapter 600 ish and told him that "hey, even though you're almost done we're gonna continue the story onwards after Naruto ends in a new series so we need you to give us some new villains to work with, ones that can threaten Naruto and sasuke as adults" And then he came up with the Otsutsuki clan. That's what I theorize anyway at least. I feel like he originally intended to finish the manga with madara and the juubi. The kaguya/otsutsuki thing was probably his way of connecting the series with Boruto so that both series fit in together. Edit: Btw, about the sage stuff, are you talking about sage mode in general or the tools that the kinkaku/ginkaku guys were using?
AND DEY SAY ZULUL AND DEY SAY ZULUL AND DEY SAY ZULUL