What reason for precursor species to seed uninhibited worlds (besides terraforming)?
What purpose for an ancient advanced species to seed planets with life (besides terraforming)? Is it some part of a grand experiment or is it because of their religious beliefs or just because they want to flex their technology? Do you have any examples of this in your own worldbuilding?
For my example, I have an ancient species called the Lehmä were once extragalatic refugees whose Galaxy was destroyed 8,000 years ago by the "Dread" whom they were running from until they came across the rogue planet of "Utero," and on it was a mystic substance called divine leche which granted them powers that they use to defeat their pursuers.
Their beloved leader, Mayya or "Lord Sage" who was the one who discovered the Divine leche, abolishing the caste system and outlining a new constitution, improving quality of life, and teaching the first generations of the mancers, hosted a mass celebration on Utero for his people. Speaking on equal footing, Mayya would announce his plans to construct a new galaxy for his people to live in and to populate it with life as to symbolize their newfound prosperity and happiness, and a desire to share it with their creations.
After five decades of acquiring the accumulated power from the divine leche, he summoned the entire Lehmä race to watch in attendance. Within a second, his audience would be blinded by an intense radiance that lasted for several minutes, and after regaining their sight they would see their new galaxy above them. The lehmä would enter into a rapturous cheer that turned into a quiet mourning as it is revealed their beloved savior sacrificed himself in order to bring upon their new home which would be forever known by its inhabitants as "Prospero."
After his father's death, his son Indrad would continue his father's promise to seed potential worlds with life, his first order of development s the establishment of an interconnected network of celestial bridges called "Lokas" created by units of lightmancers whom he superintend to make transit time between planets with easier. After that he would send units that primarily consist of elite biomancers alongside with other auxiliary mancers to assist in the evolutionary process to worlds that were deemed perfectly suitable for hosting complex life. This plan would take only a century to finish