Most customers aren't dine in at a coffee shop. I would also be careful with the claim that it is cheaper to wash, mugs are heavy and require the same: gather/

Most customers aren't dine in at a coffee shop. I would also be careful with the claim that it is cheaper to wash, mugs are heavy and require the same: gather/create/transport the raw materials, produce the cup, etc, store it in a warehouse, transport to the restaurant. Periodically replacement of broken cups as well. Silverware makes good sense as it is not usually subject to being broken, only lost or stolen.