Epic Meepo
Hero
From an in-world perspective, finite astral dominions and infinite planes are very different, but I haven't seen you making any prior arguments about in-world perspectives. Apologies if I missed it. From what I can tell, you've been arguing that the World Axis is superior to the Great Wheel as a game object: it's a better setting for adventures and it's easier for players to remember.Pretending that astral dominions are in any way comparable to the 17 outer planes and 18 inner planes and 3 interstitial planes and 3 or 4 additional planes is just fundamentally disingenuous.
There are five planes (plus one un-place) in the World Axis. There are, particularly with 5e's kludgy insertion of 4e ideas like the Feywild, more than 40 in the Great Wheel. The Great Wheel puts ALL of those 40 planes on equal footing. The World Axis absolutely does not put Mount Celestia on the same footing as the entire World. Mount Celestia is at best one (small) region.
This would be like saying that a Forgotten Realms where Neverwinter, Waterdeep, Amn, Rashemen, and Calimshan are all infinitely-large Ravnica-style city-planes is in no sense more complex than the singular FR world. Of course it would be! Each of those places is an entire plane unto itself!
I contend that neither of those claims about the World Axis are true. Running an adventure where players teleport a thousand miles across a finite astral dominion is no more or less difficult than running an adventure where players plane shift from one plane to another. The quality of adventure sites at the destination is the same, whether you have five planes or five million planes.
And it's somewhat disingenuous to argue that it's easier for players to remember all the details of the World Axis cosmology than it is to remember all the details of the Great Wheel cosmology. Replacing forty named planes with forty named astral dominions doesn't reduce the number of location names players have to remember. The name of an infinite plane is still just one name.
And if you're going to argue that players don't have to remember all the astral dominions to understand the World Axis cosmology, I'll counter that players don't have to remember all the inner and outer planes to understand the Great Wheel cosmology. Those planes are just self-contained locations divided into three buckets: the Material Plane, the Inner Planes, and the Outer Planes.
The OG Great Wheel divides the multiverse into five parts: the Material Plane, the Inner Planes, the Outer planes, and two transitive planes. The World Axis divides the multiverse into five parts: the Material Plane, the Elemental Chaos, the Astral Sea, and two material echoes. Both cosmologies sort all locations in the multiverse into five distinct, easy-to-remember regions.
Likewise, a version of the Realms where Neverwinter, Waterdeep, Amn, Rashemen, and Calimshan are infinite city-planes is just as easy to explain as one where they aren't. Players still have to remember the same number of location names. DMs still have access to all the same adventure sites. All that's changed is the mode of transportation you need to get to certain places.