It basically went from "Sasuke Uchiha" specifically to being all about the "Uchiha Clan" in general and Sasuke just got lost while all mixed in together with it, So basically everything mentioned about the Uchiha Clan in general could then most likely just be slapped on Sasuke because, obviously, he's born from the Uchiha Clan and so you don't have to continue to think up things pertaining specifically to him.
The whole point of his character early on was teeter-tottering between continuing his pursuit of fast vengeance or partially letting it go and seeing what he had right in front of him, be patient, get stronger for new purpose, and if he does come across Itachi, fight him and maybe kill him. Of course, he ultimately chose his quick and easy path of revenge, but once that goal was no longer in the picture (by Itachi's own hand really, not Sasuke's) and all that time was spent solely focused on that vengeance trip, then there was literally nothing else for Sasuke to do - no point to his character anymore really - and so they simply just kept throwing in revenge plot after revenge plot with Sasuke because they never bothered thinking of anything else for him, much less how to re-integrate him into what was SUPPOSED to be the main plot around Naruto himself.
And that is in due part of a vicious and illogical paradox of Kishi wanting Naruto and Sasuke as rivals so fueled by their desire to one up the other that it escalates into a bitter conflict, yet INSISTS on having a "flowery, gum-drops and rainbows fantasy" that the two are BEST FRIENDS that could never admit this secret exclusive bond to anyone, not even to each other and that was forced to be the core aspect of the series. The most IDIOTIC part is that you can't have it both ways because it is both self contradictory and stupid, but Kishi INSISTED it was like that and was talking out of his @$$ a lot of the time regarding his intentions of what the series is about