According to this chapter, why do great souls like Sai Baba even bother taking on a physical body if they are beyond birth and death?

Chapter 43 clarifies that the incarnation of great souls is a deliberate act of compassion. The text states that they take on various avatars 'with the sole desire for the welfare of devotees' and for 'the sake of the devotees’ protection.' Their appearance in a physical form is not due to karmic compulsion but is a willed act. The chapter notes, 'The rise of such Great Souls has the welfare of people as its purpose.' Once this task of helping and gathering people is complete, they do not 'die' but simply merge back into their true, unmanifest form, having fulfilled their purpose.