When you are a single person, the math changes. It can be cheaper or even break even to eat out every day. Especially if you lack the ability to eat and/or store the minimum package amount before it goes bad. This was a massive issue in my youth before I could save up buy stuff to make things last longer in the freezer while still tasting good. It was literally break even to cook vs eat out. Thus it was actually more expensive to eat out because we have to factor the time I spent cooking and I ruined food a lot as I learned how to make and store well what I liked.

As someone with a family now, it could never work. Even without just being better at cooking and preserving food, I can buy bulkier items that have a lower cost per unit.

I guess if I were truly destitute as a young adult, I would have cooked, but I wasn't. I wanted to have s nice salad wrap and/or hot meals fancier than beans and rice.