Why do saints incarnate when people become overly focused on worldly happiness, according to Chapter 4?

Chapter 4 of Sai Satcharitra explains that saints incarnate precisely when humanity loses its spiritual direction. This happens when people come to see wealth, status, sons, and spouses as the only sources of happiness and completely turn away from the thought of their ultimate spiritual goal, or Paramartha. In such times, people lose the chance for ultimate well-being due to the decay of religion. As described in Chapter 4, saints take form specifically to awaken religion and guide humanity back to the path of self-upliftment, protecting them from being solely obsessed with lust and hunger.