But isn’t that how it’s set up already?
Hell is all lawful and the abyss is all chaotic? Etc..
I’m not disagreeing with you. Just wondering if you feel the way the planes are set up in D&D is the result of lazy design or if you mean something different.
I start with the story and don't worry about the labels. When the Great Wheel was designed, they started with the labels and then wrote stories that fit the labels - but those stories were all over the place and lacke inspiration. This is one of the reasons why so much of the Great Wheel sees very little use.
Let me share an example of how I approached the Planar Design.
I don't have a Hell and an Abyss - they're part of the same plane.
Long ago there were only devils - creatures that followed the fallen Angel Asmodeus. They lacked free will and were bound to his service. Then, the Far Realms collided with the Prime Cosmology and shattered it. The point of contact was in the Hells (a singular plane where Asmodeus oversaw the souls of those not allowed into the Heavens - also a singular plane), and there is a rift there - in the center of Hell that has to be protected less it be torn open fully and the nightmare residents of the Far Realm find their way into the Prime Cosmology.
When that collision took place there were several impacts. One of those impacts was the corruption of some Devils into Demons. They were pushed away from the rift by Asmodeus' forces, and 9 regions of Hell were established to protect the rift - Nessus at the center, then 7 more realms in a circular pattern surrounding Nessus, and the circular battlefield of Avernus that encompases those 8 regions. Beyond those realms are the various realms of Demon Lords and other denizens of the Hell Plane. They stretch on and on and create hundreds and hundreds of regions that serve various Powers - but many focus on capturing the rift at the center of Nessus. As time goes by the battlefield of Avernus pushes into Demon controlled terriotory and and more 'land' is stabilized so that it can be pulled out of Avernus and be considered part of the other 7 regions of the 9 Hells.
The 9 Archfiends that control the 9 Hell Regions are all in the service of Asmodeus - although they plot and scheme. Some are clearly tyranical and fit into the idea of LE. Others are less regimented and might be described as CE, NE or LN. However - their followers - the Devils - lack free will and are thus all very lawful.
In the mythology of the world there is debate as to whether Devils are truly evil because they lack free will. Asmodeus argues that everything they do to collect more souls is in service of the fight of the Blood War - and the Ends Justify the Means. He considers the entire operation of the Hells necessary as it is the only way he can accumulate enough resources to continue to fight the Blood War and drive back the Demonic Hordes. It isn't that Asmodeus claims to not be evil - he just has no time for silly labels when there is a war to fight. Of course, Nessus itself if far removed from the front lines - and my Nessus has more in common with the descriptions of Olympus in Lore than is does with the descrition sof Nessus in the books.
This story has a lot of commonalities with the Great Wheel - but the reasons for the structure are very different and tell a very particular story that has been really useful over the 30+ years I've used it. I don't have Heaven Planes and Fiendish Planes there just to fill out a particular spot on the alignment scale - they all have purposes.