[[ Sasuke does care for Itachi absolutely more than he does for any other person.
But one of the reasons he has such a strong tie for Itachi is that his parents died when Sasuke was young (obviously we all know this,) but Itachi stayed alive.
Thus Itachi’s life means more to Sasuke emotionally– especially when Sasuke finds out the truth. Sasuke just never got the time to bond more with his parents, as they were also dealing with their own problems (Fugaku with the clan and rebellion, and Itachi; and Mikoto also wanting to help with the rebellion.)
I don’t think Sasuke would’ve bonded more to his parents as opposed to Itachi in a non-massacre scenario anyways, but it would be a less severe divide.
This isn’t saying he doesn’t care for his Mother and Father. Of course he does– they’re his parents and it’d be amazing to have them back, it’s just his feelings for Itachi are at a severe level. ]]

