The TES cosmology outright states that Aetherius is crystaline order, and Oblivion is chaotic potential.
If you dont like it, I suggest you complain to MK. :icecream:
Last time I checked the Daedra in Oblivion fear to touch the void and nothingness of it so they build realms out of the all magical scraps they can collect from the unlimited potential of Aetherius .
Unlimited potential when stored up might be crystaline, but just as Oblivion isn't devoid of magic, neither can Aetherius be so full of it that everything becomes crystaline.
If anything, on the edge of Oblivion and Aetherius there is going to be a [censored] storm where magic hits the void and the magic is given room to act out it's potential, creating an inferno of random creation. Some bubbles might break of and escape unscathed and form new pocket realms, atleast until all the magicka has been bled out of them by the void, or when they're harvested by the Daedra Lords.
A mortal entering Aetherius without some sort of protective void would instantly die as the stored up potential finds void it needs to act out in relative void of the mortal.
If anything, Oblivion would seem like paradise when compared to Aetherius.