It's easy because it's easy. It's light, hassle free and generally really really easy to do within time without pushing yourself, I love it when I'm rarely put on any of those aisles.
Hardest(on your own) are produce, certain fresh aisles and maybe drinks on bad nights. Oh and Warehouse if theres not two of you, but unless you are hugely shortstaffed, that should be a rareity.