But coats can be squeezed in between or laid across other bags. Bags can’t. That’s why they always ask to wait until everyone has their bags in before putting coats and jackets in the overhead bins. (Of course, not everyone listens.) Or laid across your knees like a blanket. I get that something seems obvious but that’s asking them to make a case by case judgement on everyone who boards with more than 2 items. I do see their logic in just having a rule.
I often take a small crossbody handbag with me when I’m traveling, but I always put it in my backpack before i board.