When my family grew (2 kids) it became important to me to stop eating out so much. Mostly because eating out with a 2 year old is torture. So I started cooking at home every night. It's easy to do if you plan a menu for the week. I have some common items in the pantry, and I buy meat in bulk every other weekend. I'll run to the store on a weeknight to buy fresh fish, or for the occasional forgotten item. But more or less I just get it all done in one trip, I plan the menu around common ingredients, and I choose things that don't take hours to do. I spend $80 a week on groceries (cut out boxed up processed foods and your bill gets cheap)

Families have been cooking dinners for a long time. Nothing new here.

Tasks like "plan a menu for the week" or "go grocery shopping" are the sort of thing where it's a relatively fixed amount of time whether you're shopping/cooking for 1 or for 4 -- i.e. there's an economy of scale on that time.

For me, given the choice of "$30 + the time to plan meals and go shopping" vs "$60", I'll take the latter.

If I had a choice between "$80 + the time to plan meals and go shopping" vs "$160", that time is worth a lot more money.

In addition, set all of this in a New York apartment, where the ability to maintain a well-stocked pantry is limited.