did itachi let sasuke win?
Yes, Itachi did let Sasuke win because he loves his younger brother. Most of the time Itachi did not understand Sasuke’s emotions and feelings but that does not the fact that he loves him.
Even Tobi/Zetsu mention that everything went according to Itachi’s plan. From baiting Sasuke with genjutsu to making sure Oorochimaru was sealed away permanently, just about everything went as Itachi planned, so he definitely ‘won’.
Itachi let Sasuke win, but still tired him out to make him use the Curse mark, so Itachi could destroy Orochimaru and free Sasuke from the curse mark.
So the terrorist organization that was Madaras powerplay to get his vision to fruition even though he wasn’t strong enough to forcefully change the first Hokage’s viewpoints. Was foiled by the genius Itachi. Prior to this, there was an upcoming incident in Konohagakure with the Uchiha’s plotting a coup, Itachi being a kid torn between clan hatred and being part of something bigger an alliance between clans.
Went down the path of the first Hokage and thereby set the path of his generation. His whole life was one big sacrifice from beginning to end. A sacrifice of ending old ways to let new ones grow. He took the blame for horrendous doings, trying to follow Danzo’s orders to bury the past, so the future could thrive. We later see him disbanding this path to join Nagato.
Akatsuki is the past that was buried, the embodiment of it all, Itachi even saw through it all and learned about Madara’s plan. He then proceeded to set Sasuke and Naruto on the right path to foil the ballads of the Edo Tensei.