The only reason sasuke would beat itachi now is cuz he went blind n got itachi eyes.I they were both at full power sasuke would lose just by itachi looking at him.Yes Sasuke has surpassed Itachi. If they were to fight currently Sasuke would win, he has broke out of Tskuyomi with 3Tomoe Sharingan, he has much more stamina and chakra reserves than Itachi. He can keep his Susano'o up longer than Itachi plus Sasuke has the faster jutsu's such as Blaze Release:Magatama,Susano'o Arrows and he has a stronger defence than Itachi as Sasuke has shield of black flames on his Susano'o to keep Itachi back.