The American economy is one of the strongest in the world... It's not even a debate. The challenges that face U.S. is the inefficient deployment of its resources and inability of the government to provide basic common goods to its citizens. The main ones of course being affordable housing and healthcare.
I've made fun of people complaining about food costs before in this thread and I'll do it again. I have sympathy for American poor, but paying marginally more for food isn't why they're poor. They're poor because housing is becoming unaffordable and frankly, most poor people are shit with money or knowing how to move up in the world.
It's more than just housing or healthcare. It seems like every sector is becoming more of a monopoly, so they charge as much as possible because there is no competition.
Plus part of it is the culture with the constant advertising which makes people feel they have to keep buying and spending. Coming from Europe or Asia, the amount of advertising in the US is really noticeable