Possibly, but I think the source material we have for D&D 5e contains a lot of different examples of dungeons, what they were built for originally, and what they are used for now. From even just there, the mind races thinking of all sorts of other fantastical possiblities - a manifestation of a dying god's fever dream, a part of the world so corrupted the realm itself has made of it something of an abscess, a crashed spaceship buried under rock (heck yeah!), a power plant from a lost civilization in the form of a pyramid. Sky's the limit!could also be failure of the source material to communicate adequately. Or failure of the source material to present that info in-game adequately. I suppose it depends a good deal on where you sit. DM, player, writer, artist.