Consistent as he stays true to himself. He of course faces hardships and changes when he overcomes these challenges. Naruto ain't consistent because he went form "I'm going to be hokage despite all my setbacks" to I'm the second coming of Jueus and everything was according to prophecy. Same with luffy. You are introduced to an adventure loving free kid, but in the end he's a slave to the Nika df. Only Ichigoat is Consistent, it is what it is. 🤷
You're mixing up apples and oranges there. Naruto has always been consistent with what he wants and how he wants to get it - those are the traits of his character.
Reincarnation stuff got introduced later with the Kaguya
plot, and although idiotic, has nothing to do with Naruto's character traits and hasn't changed his behavior whatsoever.
Essentially you're saying Naruto looks bad because of bad plot. If plot and character were relatable, then Ichigo would be the worst cause Bleach "plot" is basically nonexistent for most of the manga.
In behavior? Naruto has been consistent, but also evolving after every arc and time period. The best I can say about Ichigo is that he had to realise he has to rely on himself and that he wasn't to blame for his mom.