Although few people had heard of the Sea of Bitterness, many people knew of it. There must be many people who could come to the Sea of Bitterness.
However, there were probably very few people who could comprehend the Dao of All Living Beings.
First of all, if one wanted to comprehend the Dao of All Living Beings, he had to at least have the strength of a Sea Quelling God. Otherwise, it was impossible for him to tear the divine intent into countless pieces like Han Fei.
Secondly, a person who could comprehend the Dao of All Living Beings needed to be able to carry the will of all living beings, which almost excluded Sea Quelling Gods. The reason why Han Fei could embark on this path, and the reason why his teacher knew that Han Fei could embark on this path and was waiting for him here, was that the Supreme Will was comparable to the Chaotic World and could completely carry the will of all living beings.