"Why would we wash dishes when we can just use paper plates from Costco, amiright?"
No. No that is not right.
ETA: This was in reference to regular home use
FWIW, I have some relatives that have actually done the math of paper vs reusable plates, and it's not as clear-cut as you might immediately think. When you consider the acquisition cost, the cost of water, electricity, detergent, and the time spent washing and putting away dishes, the gap narrows considerably.
That is some pretty funny math
1 Acquisition Cost-- can you imagine not owning a single dinner plate that is not disposable? Most people have a set (as a gift usually) and then buy the paper plates too. In reality, most people would buy a set of dishes for $30, and have it last 10 -15 years. $0.01/dinner
2. Time spent washing dishes is free because I don't pay anyone to do that for me. When I am too busy (making money) they pile up or I ask someone else to wash them (for free).
3. Water / Electricity $0.17/load. Soap $0.17/load = $0.34/load. Also - do you buy plastic cutlery and how do you get the pots and pans clean, serving items without running a dishwasher..? What about cups?
Plates, cups, cutlery (disposable) for 6 persons:$0.70. (2 cents per plate, 5 cent cup, 3 cent cutlery, plus one trash bag at $0.10 per meal)
Cost to run dishwasher, plates $0.35