Alright, this is part two of my review of the official settings of D&D. The first one I covered Greyhawk, Mystara Forgotten Realms, and Dragonlance. The first three were developed as home campaign settings that were elaborated on to become settings. The fourth was made as adventures and was revealed over time. All of these were published when D&D was produced by TSR. Greyhawk was the only one directly influenced by Gygax and, arguably, could be his vision of what D&D settings should be. The rest were mostly developed by other people and sort of reflected range of what you could do with the game.
That said, all of the ones in the 70’s and 80’s at least started with certain commonalities. They all carried a flavor based on western European fantasy. You had Merlin-like wizards, knights, kings, peasents, elves, dwarves, halflings and all the other tropes one associates with western fantasy. While the sword and sorcery genre was what Gygax pointed to as his influences, it is hard to ignore how many of these tropes were influenced by the works of Tolkien. Any proper Tolkienian will tell you the elves and wizards in D&D don’t really resemble the Middle Earth versions. Their presence are elemental to the conception of the fantasy world. Simply put, Tolkien is the gold standard of world building up to that point, so anyone following him will have some similarities.
In the 90’s, and the post-Gygax era, TSR began to experiment more with their settings. They didn’t completely lose those elements and they continue today, but the willingness to experiment away from the classic western fantasy/Tolkien model is certainly there.