Scruffy nerf herder
Toaster Loving AdMech Boi
While I love your example because Eberron has a more dynamic world with more room for morally grey characters, it doesn't even begin to accomplish what Greyhawk did in this respect.Not familiar with eberron?
Why do I say that? Because in the original core rulebook and then Greyhawk, the first official supplement, there wasn't even such a thing as good or evil alignments. Governments are just governments, groups are just groups, it's like the real world the "good guys" is something entirely up to perspective.
In Eberron, you can interact with lots of evil NPCs and even evil governments. In Greyhawk, you can get to wondering whether every government is evil, even the "good guys", because the government actually acts like the government. The orcs and goblins fight you because they reject society and laws. You either uphold society or you don't, because like it or not the society you have is the society you get. Or you simply don't care about anything like that because your character has his/her own goals.
Before we made so much of the game about alignment, characters simply did human things driven by human motivations. When players were heroic it meant something, they were fighting to accomplish something genuinely important to them, e.g. saving NPCs they are fond of, etc.
TL;DR: Eberron lets you have more alignment options and presents you with NPCs of more different alignments. Greyhawk is like: "Wtf is alignment? Haven't heard of that yet." And so it throws alignment right out the window.