Why has purgatory virtually disappeared front Catholic belief and practice since Vatican II? A competitive spirituality, gravitating around the religious vocation of ascetics from the late Middle Ages, enabled the doctrine by extending the temporal horizon within which God's favorable judgment could be secured, first, in the lifelong practice of ascetics in their spiritual competition with martyrs, and then into a supernatural time required for laypersons and ascetics who could not meet the standard set by saintly ascetics. The loss of this competitive spirituality after Vatican II led to the loss of belief in purgatory and devotional practice surrounding it.
Thiel, John E., "Time, Judgment, and Competitive Spirituality: A Reading of the Development of the Doctrine of Purgatory" (2008). Religious Studies Faculty Publications. 45.
Thiel, John E. "Time, Judgment, and Competitive Spirituality: A Reading of the Development of the Doctrine of Purgatory." Theological Studies 69.4 (2008): 741-785.