Sasuke would be fodder if it weren't for Obito
This is kind of an argument toward what others call "handouts" and how people(especially uchiha fanboys) like to use during vs threads on characters such as Kabuto or Nagato. I.e. Nagato without rinnegan would be shit, or Kabuto is weakling who needed other people's DNA to be strong.
Well if Obito didn't transplant Sasuke Itachi's eyes, Sasuke would be blind and useless. He was already losing his sight after killing Danzo and fighting Kakashi.
If he were to go blind, he wouldn't be able to fight because he won't have his sharingan abilities, including predicting movement and seeing chakra nature types, and he doesn't have a sensory ability like Kabuto did to fight effectively while blind.
Sasuke doesn't have any medical ninjutsu that we have seen to replace his own eyes with Itachi's, nor would he even know the location of Itachi's body since Obito took his eyes and disposed of the body.
And considering that Sasuke was already on the verge of blindess, he wouldn't have been able to replace his eyes by himself, even if he did have Itachi's eyes and medical ninjutsu.
Sasuke should be pretty grateful for Obito saving his character.
my point is that pretty much everyone has handouts including Naruto and Sasuke, so why use it on Kabuto/Nagato/Madara