Note that they're talking about an aisle alone, not about going to the grocery store alone. My kids were older than 8 the first time they walked to the grocer

Note that they're talking about an aisle alone, not about going to the grocery store alone. My kids were older than 8 the first time they walked to the grocery store by themselves, but I'm confident that I told them "you go grab the peanut butter you like" while I was grabbing something in a different aisle when they were around kindergarten age.