That sounds really cheap, if you don't consider that you need to do all the shopping, you need to prepare all the food, and deal with probably a bunch of food waste.
He says it right after returning from the store. Like "I bought this bag of 12 tortillas, I only need one for this burrito, obviously I would be using the rest for other things".
Sure. Tortillas can indeed last for quite a long time without any particular extra effort. Those 11 unused tortillas account for $4.39. We'll take that off of the total.
The cost of the singular burrito has now been reduced to ~$30, which still seems rather expensive.
Actually given that in the US especially you would have to drive to chipotle, queue and then wait for them to prepare it, and you are already doing groceries anyway, you are exchanging driving and waiting at a Chipotle by cooking things at home. I find the second more enjoyable, but I understand that for people that don't like cooking it might not be the case.
Are you someone who has the capability to be constantly making money any time you want to? If not and you just have a normal 9-5 job or something close to it, you have plenty of time to shop for an hour once a week, then spend 10-30 minutes a day making your own lunches and dinners and still come ahead financially -- way, way ahead.
I have no idea where you're coming from with the "dealing with food waste" part so I'll just ignore it.
Are you someone who has the capability to create extra time in your day? If not and you just have a few hours of free time per day, you can choose to spend some of that free time cooking, or you can let someone else cook for you and use that time on other things you value more than saving $10 or whatever.
The strategy is dependent on what is more precious to you - time, or money. Telling someone they should spend their time to save $10 is pretty pointless if you don't know what their financial situation is and whether that $10 has any meaning.
Food waste is food that you buy which is not ultimately consumed , which increases your cost per meal. This might be trimmings, it might be something you burn, it might be leftovers you don't get to.
https://www.youtube.com/watch?v=QRtoUoBgjDw