Sure, but how does a map defeat the measures stores take to get you to buy impulse items. If you want to buy milk, there are two possibilities. The first is, you know exactly which brand of milk you want to buy, and you will seek it out explicitly. Or, you don't care, and will pick whatever's easiest. That's the area for optimization: pick the highest profit milk and make it the first one the doesn't-care-about-milk consumer sees. Put lots of impulse items on the way to the milk. And so on. A map on the phone does nothing to prevent impulse buys.

On the other hand, why even bother going to your store when groceries can be ordered online and delivered? Then you don't need a map at all.