What if Susanoo is given to the most powerful Uchiha at a time and must only exist in that person only.Notice Itachi was the first to use it.When he died Sasuke carried on.I know multiple people used it but besides Sasuke they were Edo tensei copies(Itachi and Madara).When Madara was rinne tenseid,Sasuke somewhat lost that ability(Madara stabbing him through the chest).When Sasuke recieved power from the Sage,Madara did not use it again.Kakashi later gained it through Obito and notice Sasuke never used it.