CC Ādi 5.114

deva-gaṇe nā pāya yāṅhāra daraśana
kṣīrodaka-tīre yāi’ karena stavana
deva-gaṇe — the demigods; — not; pāya — get; yāṅhāra — whose; daraśana — sight; kṣīra-udaka-tīre — on the shore of the ocean of milk; yāi’ — go; karena stavana — offer prayers.
Unable to see Him, the demigods go to the shore of the ocean of milk and offer prayers to Him.

The denizens of heaven, who live in the planetary systems beginning from Svarloka, cannot even see Lord Viṣṇu in Śvetadvīpa. Unable to reach the island, they can simply approach the beach of the milk ocean to offer transcendental prayers to the Lord, appealing to Him on special occasions to appear as an incarnation.