Mannahnin
Scion of Murgen (He/Him)
"It does little to attempt to simulate anything either. ADVANCED DUNGEONS & DRAGONS is first and foremost a game for the fun and enjoyment of those who seek to use imagination and creativity. This is not to say that where it does not interfere with the flow of the game that the highest degree of realism hasn‘t been attempted, but neither is a serious approach to play discouraged. In all cases, however, the reader should understand that AD&D is designed to be an amusing and diverting pastime, something which can fill a few hours or consume endless days, as the participants desire, but in no case something to be taken too seriously."
Some parts of D&D definitely were designed to conform to elements of the real world. If you dig into it, a lot of the basic math around pieces of it does confirm to real world sources, though often consciously simplified for ease of play as Gary suggested. I remember people breaking down the Jump numbers from 3rd ed, for an example. Travel distances in various editions were based on real life sources. The functional ranges of bows were originally imported from Chainmail, which in turn based them on historical sources. Of course, bows are a conspicuous example of an early mistake in this regard (applying ranges for effective fire at formations of soldiers to fire at individuals), which has been carried forward into the highly unrealistic ranges (or rather, lack of to hit penalties) of D&D bows to this day.
But yes, while trying to ground the game in reality where possible for greater verisimilitude and ease of player engagement with and envisioning the imaginary space, ease of play was the intended greater priority.