There used to be cafeteria restaurants beyond IKEA and corporate campuses though. In Seattle we had Bakeman's, where you could get a freshly made sandwich, soup, and slice of pie for like $11 (yes it'd be higher today with inflation, but even in 2016 it was still very cheap for a fresh meal in central Seattle). In Russia they still have stolovaya, very much like the IKEA cafeteria: https://www.tripadvisor.com/ShowUserReviews-g298484-d3201436.... I ate at them in 2009 and loved them.

I really wonder if something like a food truck serving rice & lentils with a side of yogurt for $5 a plate would be economically viable in any US city. Some people just want food that tastes OK, is fairly healthy, and frees them from doing dishes that night.