There's also the family that uses mayo and only goes shopping once a month or whatever. Some of those bigger jars are something like two normal sandwiches a day for a month, which is totally possible if you're packing lunch for two kids.

Some of our preposterous containers of food are because some people decide to live unreasonably far from a grocery store, or just go shopping infrequently and buy huge amounts of food.
(This has the side effect of making them buy bigger cars to hold the groceries and family that now has to come along because it's such a long trip, and that makes it miserable so they try to do it as infrequently as possible, so they need to buy a lot of groceries to hold them over. )

I haven't seen anything under 20oz in my supermarket, but I'm not buying the fancy "organic" stuff, just the squeeze things for picnics and the larger jars for home.

Maybe don't eat the mayo in the doomsday prepper bunker.

or dudes that just really love mayonnaise, I guess.

You know it's nice to be seen

Out of curiosity, I just checked my pantry. I have two 30 ounce jars (1400+ grams), sitting in reserve.

This genuinely represents a failure to comprehend the scale of American food products.

They're not lieing... this is literally the first thing that comes up if you search mayonaise in the US.

Restaurants use a 10 gallon bucket (37.8 liters).