There's the opportunity and comfort cost as well though. I can definitely see how one could see spending $5 on a box they can grab from the drive thru and immediately throw away is a better choice than going to the store, meal planning, ensuring there's proper refrigerator and freezer space, making sure the perishables are used, and then also taking the time to clean the dishes used afterwards.

$5 for a few minutes of effort vs spending slightly less for usually at least half an hour to an hour when off hours during the work week are at a premium can make that extra spend very attractive, especially if they're single