I’m not a fan of the “sells:*” tags because they don’t match with the way we usually document things and I couldn’t find a list of proposed tags in this scheme.

There is Key:vending - OpenStreetMap Wiki which is mostly used for vending machines. The wiki has a list of many goods and the concept could be used outwit the context of vending machines, too.

OpenLevelUp/Use cases/Shopping mall - OpenStreetMap Wiki suggests vending + department=store_section but the key department is used in other contexts, too.

I’m in favor of vending in combination with some other tag. Maybe vending + shop_section=counter. This way shop_section values could be used to map other shop parts like checkouts, too. We also should not limit this to foods - there’s also big DIY stores, vast tree nurseries and department stores selling clothes, food, garden stuff, …