How/Why are the islands floating in Heavensward + The Aery?

[Vydos]

I had assumed that it was due to wind aspected aether. Just as the pools in Voor Sian Siran are generated by water aspected crystals. If you look at the bottom of a lot of the "islands", there are green crystals.

Mostly this. Sea of Clouds is wind aspected and Churning Mists is lightning aspected. Thats also why they have unique umbral weather, overaspected aether.

Hmm, still those explanations give little actual information and feels like it's just the "It's magic/fantasy world". While I have the firm impression that those lands either belonged on the ground once. Or were one giant floating continent. But that still leaves the question as to why and how such a continent ends up flying in the sky. And why the allagans felt like artificially recreating them in Azys Lla. Which seems to hint that the Allagans lifted (random?) pieces of land.

I know that we can all agree that those aether/crystals are what are keeping the islands afloat. But those islands must have come from the ground at some time. One does not simply create land out of thin air, stick some crystals below them and have the aether suspend them in air.