This is absolutely not true. I lived in the US (midwestern food desert) for half a year and absolutely made do with fresh tomatoes, ground beef from the counter, bell peppers, fresh garlic, onions etc. I didn't even have a car and had to walk over 30 minutes to the nearest store.

The people in my apartment were all pretty young and were surprisingly confused every time I was making something fresh from scratch. And I am by far not a good cook by any standard in Europe - I'm far from average probably.

I did the math (because I was broke) - on my "lazy" weeks where I didn't cook much fresh I spent much more money on average. I had access to 10 different fast food locations before I hit the first grocery store, this is the actual problem.