The higher one's cultivation was, the more reduced the effects of some spirit plants and medicinal pills would be, and some would even become ineffective. The fact that the Celestial Peach was effective even on those at the Emperor Heaven Realm showed just how precious a treasure it was.
Moreover, it could directly add 1,500 years of lifespan. Within spirit plants that increased lifespan, this was a top-tier effect.
The reason Zhao Fu chose this trial was because the golden dragon told him that Celestial Peaches not only gave a large amount of lifeforce, which could reduce the effects of the Emperor Killer Curse, but they also contained a trace of Celestial Source Energy.
Even though higher-beings would not care about a trace of Celestial Source Energy, it was something that even Emperor Heaven Realm experts would madly fight over. This would help him greatly in the future, so Zhao Fu listened to the golden dragon and chose this trial.