This is the kind of stuff Dave Hargrave (RIP) was great at. In between weird-ass demons and overpowered spells, he'd stick in 2 pages of "snack foods of Arduin". Such a blend of over-the-top Monty Haul gaming and man-in-the-street worldbuilding.
I feel obliged to link to this, my epic walkthrough of the Trilogy, with a few digressions. mrlizard.com/arduin/
Got a bunch of maps for the old-school Arduin game setting, recently funded on Kickstarter by Emperor's Choice. Yes, that's an Arduin-branded backscratcher. They're relaunching the game at some point, and I wish them luck.
Ah, Arduin
… so that sent a message of “we’ve given you the starting point and now it’s your job to add more fun stuff”. (And you’d get weird third-party stuff like Arduin.) But AD&D felt much more like a walled garden.