Why is the Earthly world considered more suitable for Self-realization than other spiritual planes like the world of the ancestors?

The sacred text explains that different spiritual efforts lead to different realms with varying potential for Self-realization. Chapter 17 clarifies that while practices like sacrifices (Yagya) can lead to the world of the ancestors (Pitru-loka), this path only grants the enjoyment of the fruits of karma, not the ultimate realization of the Self. Furthermore, other higher realms such as Maharloka, Janaloka, and Satyaloka are described as places where the vision of the Self is very unclear. Therefore, as chapter 17 states, those who genuinely crave the vision of the Self desire the Earthly world (Bhuloka). This is because on Earth, the conditions are ripe for the heart to achieve purity and for the intellect to become 'clear like a mirror,' which allows the pure nature of the Self to be perfectly reflected.