Why is the Guru biography by Shri Samarth Sadguru Vasudevanand Saraswati Maharaj considered to be in a different category from others?

The text in Chapter 0 makes a clear distinction regarding the Guru biography written by Shri Samarth Sadguru Vasudevanand Saraswati Maharaj. It states that this work cannot be categorized with the Guru biographies written by Shri Saraswati Gangadhar and the late Shri Annasaheb Dabholkar. The explicit reason provided is that this particular biography was written by the Maharaj himself. This implies that a biographical work authored by a Sadguru is considered fundamentally different from one written by a devotee or poet, likely due to the author's unique spiritual standing and perspective, as noted in Chapter 0.