Pretty much every D&D campaign has plenty of political and social commentary written into it, aside from hypersimple stuff like "Orc and Pie".
Take Curse of Strahd, for example. There's obsessive and abusive relationships, blind obedience to authority, a tyrant that must be assassinated, religious abuse, trampling of the rights of citizens, xenophobia, abuse of authority/power, and -so much more- that you're fighting against in the adventure.
And much of it's the same as the old Castle Ravenloft box set in that regard. The same abusive authorities, relationships, assassination of the ruler, etc, etc, etc.
Dragonlance? Authoritarian Regime against which a ragtag group of rebels battles, relying on ancient weapons from a time before the tyranny started conquering the lands. Add in a hero bringing "True Religion" back to the world, Flint representing an older, harder, generation, Tasselhoff as exuberant and often foolish younger generation... Heck, Tanis Half-Elven is -literally- a person of different heritages who doesn't fully fit in with either side and fights himself over it as a mixed-race character.
Dark Sun. JUST DARK SUN.
Eberron is built from the ground up around intrigue, war, politics, lost kingdoms, foreign cultures that aren't inherently evil, false gods, true gods, economic and political power falling into the hands of a literally gifted elite who keep tight control over their noble houses and economic interests (the mystical 1% you might say), and so much more...
But even Greyhawk had political messages about the role of women in society, xenophobia, racism, cultural identities, tribalism, the inherent structure of a class based system and how it is supported in the narrative through the acquisition and exchange of land for service in a feudal society, and just so much more.
Take even the idea of "gods" in the FR setting. They're all based on Quasi-Roman deities (With a pantheon for every group and a new Elf god (Or Elf-God-Sub-Pantheon!) for every type of elf there is... except there's also an all powerful AO (Alpha Omega, unsubtle hint). But almost every setting follows the same general pattern of gods that control this or that aspect of life across the globe/universe/planes. Why not a monotheistic or duo-theistic world? Why go explicitly -away- from that design (though it was offered as a structure in Deities and Demigods for 3e) even though it's one of the most popular structures in the real world?
Because of a conscious or subconscious decision to reject what is "Real", or at least widely accepted, in favor of what is "Fantastic" in relation to day to day life.
Yeah, a lot of it can also be boiled down to "It's a setting with a lost golden age" but you realize that's just us, right? There's entire political movements that want to go back to a mythical golden age of (insert country/culture/society/etc here)
But, like... Practically everything we consume in media that has any structure or narrative is going to be based on the experiences and perspectives of the writer... Which includes their political identity, religious beliefs (or non-belief), and moral and ethical ideologies. It would be impossible to not do that, because those things shape us. All of us. To degrees we do not think about.