The only way to solve the problem of the Celestials for good was to find where they were and wipe them all out in one sweep. Otherwise, if the Celestials returned at some unknown time, it would become another disaster.
That was also why Robet had chosen to pursue Thanos before. If a potential threat was not dealt with, Robet himself was not afraid, but the people around him would inevitably be affected.
As for why simply contacting the Celestials would not work, the main reason was that, as far as Robet was concerned, the Celestials had no credibility whatsoever. Robet had not forgotten that when Exitar spoke with him back then, he had said that Earth Dimension Consciousness had nothing to do with the Celestials.
It could even be said that from the moment Robet met the first Celestial, the Celestials had been acting. Even their appearance before Robet was because Robet's strength was too great, making the Celestials worry that Robet would come knocking first and put them in a passive position. That was why they had appeared before Robet to communicate, while also probing him in passing.
Only, the Celestials had not expected Robet's strength to grow so quickly, nor had they expected him to so easily find the Cosmic Void. That made it very difficult for the Celestials to find a place to hide or a chance to turn things around, so they could only leave the current universe and go try their luck in another one.
"Fine!" At that moment, the newly revived Celestial seemed not to understand Robet's intentions—or perhaps he did know, and understood that if he did not agree to Robet now, there was only one fate waiting for him.
Since he did not want to die, the Celestial could only helplessly