I am not disagreeing with anyone here. When I stayed with my daughter in SLC 2017-2018, we lived within 3 or 4 miles of 7 grocery stores that were shopped. I happily did every one of them, week after week, and after working all day! There was generally a "required" purchase that left room in the reimbursement for one or two staples for the pantry. I used the required purchase at the deli to pack lunches for my daughter and son-in-law.
I carefully explained to them how the reimbursement wasn't taxable income to me, and by working for MSCs with fast pay, I could "turn" that initial out-of-pocket over again and again and again.
They both worked full time. They ordinarily spent $7-$10 a day on lunch. Each. Or, looking at it another way, $70-$100 a WEEK on lunches. With housing costs in SLC so high, student loan debt, buying a car, health insurance, a new baby, etc., my grocery store shops allowed them to direct an additional $300 a month to their student loan debt, enabling them to pay it off several years earlier than just making the minimum payments (minimum payments actually result in a life-time of student loan debt slavery, LOL). And the shops cost me NOTHING. (I will add, I offered to pay them rent, and they didn't want it, so this was my "way" of contributing.)
However, as I stated above, I now live 45 miles from the nearest shop. What worked in SLC does not work in rural Nebraska.