I think you're missing the point mate. LOL, they never said they didnt need him yes they needed him but he has said they weren't needed and it be better if they die off but in this last chapter if they weren't there (Sakura/Kakashi/Obito mainly for this argument) he would have already been dead and the world ended so they needed each other. If he knew how things would play out he would have also NEEDED to save them as well cuz they were the only ones that could HELP PROTECT HIM.
Not ONCE did Sasuke say it would be better to let anyone die. (if you're talking about that line where he supposedly said they should've used the kunai on Obito, that was a mis-translation by Manga Stream. According to the Viz translation he said the kunai is holding up Obito.)
What he DID say was there was nothing Sakura and Kakashi could do which was TRUE at the time.
He also said Kakashi and Sakura got saved only bc they happened to be next to Naruto.
Well, what's wrong with that? Was he supposed to go looking for them and allow Naruto to fall under the genjutsu at the cost of the world?
Lastly, let's not pretend this whole situation wasn't FORCED by Kishi to make Sakura useful (she was due for a bone throw...you know he likes to throw her a bone or two every hundred chapters or so)......and to give Obito an honorable exit.
I mean, how did this whole thing progress the plot any way? What did we learn?
And come on man. Kishi could've easily used the kages to save Sasuke (clearly the Sage is about to give them an ability to enter Kaguya's dimension).....or he could've have Naruto's clone follow Kaguya through the dimensions and have her keep switching dimensions to escape until they end up when Sasuke is and they work out some sort of plan to stay together.