I spend about $75/week for 4 people. Granted, we bought a cow 15 months ago, so a large chunk of meat is from that, but...
You eat like I do. My oatmeal (or quinoa) typically has stuff in it - seasonings, berries, nuts. But lunch is usually a bowl of cottage cheese with some seasoning, or the last few days its been a granny smith with some PB. Dinner for me sounds a lot like yours, too. I am a pescatarian, so it is usually a small salad with some kind of protein in it - cottage cheese, shrimp, eggs, etc. If it was just me that I had to feed, I could easily get by on $5/day.
I have 3 boys - 2 teens (both 6'4, 265+) and a husband of the same size. I meal plan, shop around sales, and cook simple, healthy things. A 2# pork loin would yield leftovers, because I make so many "cheap sides"....veggies, salad, usually some quinoa or lentils. I always make "a leftover container" before they even dig in so that it is out of sight, out of mind.
I grocery shop Aldi each Monday for between $50 - $75, and then Costco 1 - 2 a month for my almonds, the block cheddar, a chicken or two to make pasta salad with (lunches for the fam), sour cream, and in the summer, I get my son his fave tortilla chips and some shredded cheese so he can have his daily nachos that he makes with leftovers from the night before. Otherwise, I do not buy shredded cheese the rest of the year...that kid can shred it by hand
Just got a bunch of eggs - they are under $1/dozen. Will hardboil up a few containers for sandwiches, salads, quick breakfasts. Will make an egg bake or two, and many meals will be taken care of for well under $10.
I feel for people who live where they are still outrageous. Our lake place is in small town and their groceries are EASILY 3x the cost and the wages are half of what they are here. I can see how people can get jaded, thinking nobody is able to survive.