The progression of manga stories.
The series is called Naruto.
Naruto will be the most powerful shinobi by the end of the series.
He is the main character, and his qualities will always outshine everybody elses, even if they share the same qualities.
Sasuke is the antagonist.
As such, he will be treated like one and given powers to keep him on Naruto's edge.
No matter how low he may have fallen before, he is still who he is, like it or not, and people love him.
Naruto and Sasuke will, and will always be the most powerful characters in the manga by the end.
In a story, it usually starts off introducing everybody.
So everybody is given equally important roles.
As the story progresses, the main character will continue to get stronger and stronger.
As he gets stronger and stronger, the focus will zoom in on him more.
More of the villains focus will begin to target him, and the story will evolve around him more.
To confront these villains, the main character will have to get stronger and stronger. He can't stay the same weakling he used to be and re use the same tactics over and over again. He needs more fire power.
Along with these things, as the story progresses the side characters will get less and less time to shine, and the time they do will be in short bursts or in rare cases, and entire chapter dedicated to it so that they aren't entirely forgotten.
The point of this is to lay out some cards we all need to realize because some people just don't get it.
Naruto and Sasuke will soon be the strongest, deal with it.
The cutsie ninja theme they had at the beginning hasn't been abandoned, it's just taken a new theme of never going back. Deal with it.
They will have to get stronger and stronger to fight new enemies. You think kunai and wire tactics will work against people like Juubito? Deal with it.
Side characters may get the shadow treatment in favor of strengthening the main characters. Deal with it.
Plot twists WILL take place and things you don't expect to happen WILL happen to keep the fans on the edge of their seat. Deal with it.