Siddhashila does the work that heavens do in other traditions while refusing almost everything that makes them heavens. There is no reward there: the siddhas do not enjoy pleasures, since pleasure belongs to embodiment and they have none. There is no society: each liberated soul abides in its own omniscient bliss, and the texts do not describe conversation at the summit. There is no administration: nothing is granted, judged or heard from Siddhashila, and Jain worship of the siddhas, including the daily homage of the Namokar Mantra, is explicitly veneration without petition, honoring exemplars who cannot and need not respond. The contrast with the heavens below is the tradition's own emphasis.
Jain cosmology is generously supplied with paradises, tiers of them, filled with long-lived gods, and it prices them accurately: heaven is a good rebirth, and a dead end, since liberation requires a human birth in the middle world. The gods themselves, the texts say, envy the human station. Siddhashila stands above the whole stack precisely because it is not one more level of reward but the exit from the economy of reward altogether, the permanent state of souls that have stopped accumulating anything. In the comparative record it is a rarity, an apex that is a condition rather than a kingdom, and it makes the Jain map unusually honest about its own values: the top of this universe is not where the best things are, but where nothing further is needed.