1. Potential for less waste through 1) people not avoiding ugly produce, 2) not leaving refrigerated stuff on a non-refrigerated shelf, 3) leaving freezer doors open, 4) stealing things.

2. Less congestion in the browsing section.

3. Better stock tracking.

4. Easier stock management. You don't have to have people move stock between a warehouse and a shelf.

5. And yes, you don't have to push a cart.

There are significant drawbacks too. The biggest one I can think of is that the fulfillment mechanism doesn't actually exist.

Imagine being able to open a Walmart Supercenter in the middle of, say, San Francisco(like that would ever happen but anyway). They'd never be able to afford the real estate for a traditional supercenter, but they might be able to afford a super-tower.