What are the spiritual benefits for ancestors and descendants from observing Pitru Paksha?

For ancestors, observing Pitru Paksha is believed to provide their souls with nourishment, peace, and help in their onward journey, potentially leading towards liberation (moksha). For descendants, performing these duties brings blessings from ancestors for health, prosperity, longevity, progeny, and overall well-being, while also alleviating Pitru Dosha.