Can you compare the different types of biographical writing and their spiritual benefits as described in the source?

The source material in Chapter 0 outlines a hierarchy of service through writing. At the base level, writing biographies of worldly figures like writers is a worldly service with limited, non-eternal fruits that are rooted in self-interest. A higher form is writing the biographies of many saints; this is a form of Guru service that yields spiritual fruits, but is considered partial and insufficient for attaining the ultimate spiritual goal on its own. The most superior form, which grants the fruit of salvation, is writing the biography of one's own Sadguru and engaging in its devotional study.