Indra is known for being solo. Sasuke was also solo during the war in juubito battle. Recently in the new chapter Sasuke changed. On 689 Sasuke tells Naruto they should use team work
Madara had the whole Uchiha clan then had Kurama when he was Indra's transmirgater and Sasuke had team 7, Orochimaru, Taka, and alliance so when have Sasuke been doing things himself in a long run? He needed Taka to fight Bee, needed Taka+Gaara to fight and survive against A, needed White zetsu and Obito to survive the Kages, Needed Karin to heal him to fight Danzo, needing Obito and Zetsu to escape team 7, needed the alliance to help with Juubito. Need Naruto for Madara and Kaguya.