Why are the fields of asphodel and the fields of punishment more crowded than the isles of the blest?

In Greek mythology, the Fields of Asphodel are inhabited by ordinary souls who lived neither virtuous nor wicked lives, while the Fields of Punishment are reserved for those who committed grave sins. These realms are more populated because the majority of people lead lives that fall into the gray area of morality, resulting in a fate in Asphodel. In contrast, the Isles of the Blest are reserved for exceptional souls who achieved great virtue, making them far less populated. Thus, the more common outcomes of life lead to a larger number of souls in Asphodel and Punishment compared to the rarified existence of the Isles of the Blest.