Does writing biographies, even those of a philanthropic nature or of many saints, guarantee the attainment of the ultimate spiritual goal?

No, it does not. The text makes it clear that while some forms of writing are a type of service, they do not guarantee salvation. According to Chapter 0, writing biographies of worldly figures, even if it involves public education and philanthropy, is rooted in self-interest and does not yield spiritual fruits. Even writing the biographies of many saints, while a form of Guru service, is described as partial. The text explicitly states that it is difficult, or rather impossible, to attain the ultimate spiritual goal merely through these types of writing alone.