If it were only about efficiency, you'd probably just eat beans and rice, day in and day out, with a bit of this and that thrown in.
Edit: BTW, this book has some interesting ideas about the US and food: http://amzn.to/2oVeaYz
Among other things, he points out that the US does have slow food with a high degree of regional variety: barbecue.
There's some interesting coverage of BBQ as an exception to the homogenous, fast-food culture in the US in Tyler Cowen's book "An Economist Gets Lunch": http://amzn.to/2nZDa0k
Where I'm from in Oregon, there are a few places, but they're few and far between, and I doubt the quality measures up to areas where there is more knowledge and competition between establishments. Indeed, I have to admit to having had absolutely no clue about real barbecue growing up.
I think it's pretty cool that it's such a local thing, in an age when so much of life is so homogeneous in the US.
A famous economist / foodie has written an entire book about how you've got it EXACTLY backwards:
The best food, he asserts, is in strip malls. You just have to know a few tricks to find it.
Great book. Go read it.
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