Eberron is probably my favorite published D&D setting.
I like the dragon marks and the dragonmarked houses. I love the take on religions. I love how it presents a more modern take on fantasy, moving away from the pseudo-medievalisms. I like how it can accommodate everything in core D&D, but still feels coherent.
And I absolutely love how the timeline remains fixed at 998 YK, without having to endure all sorts of nonsense trying to justify the rules changes between game editions. Or any sort of metaphor. I love how most of the big mysteries in the setting are hinted at but ultimately left up to individual DMs to determine.
I also love how it has its own cosmology, specifically tailored to the setting
From Fizban's Treasury of Dragons (page 7):
The myths of Eberron describe the involvement of the three Progenitor Dragons in that world's creation: SIberys, the Dragon Above; Khyber, the Dragon Below; and Eberron, the Dragon Between. These godlike beings are said to have created a microcosm of the multiverse in the depths of the Ethereal Plane, sequestered away from the Outer Planes and all the influence of the gods and other cosmic powers. Viewed through the lens of "Elegy for the First World," Eberron is thus not actually a fragment of the First World, but a second generation of that original realm- yet even Eberron is profoundly shaped by dragons.
Thus, Eberron's cosmology is a multiverse within a multiverse.
And thus I intensely dislike this. I don't have that book, and had never read that quote until just now. Of course I can and will ignore this... But it borders on irrational how much it annoys me.
This adds absolutely nothing of value. Eberron exists in a pocket of the multiverse, completely isolated. What exactly is the point in that, other than to appeal to pedants who need everything to be connected somehow? It's wordy, ungameable lore and is completely pointless.
I recall that 2e Spelljammer had a similar thing with Athas, saying that it existed but was completely inaccessible. Thanks, that's really useful information that will make for memorable gameplay!
Why does everything have to be part of the D&D Multiverse? Why can't a setting just exist on its own?
Anyway, Eberron is awesome, and I'm just going to keep ignoring this whole Multiverse stuff, because I think it's silly.