Rich and wealthy and middle class and poor aren't rigorously scientifically defined terms, the only one that is, is that the US Department of Health and Human Services (HHS) has a definition for poverty wages, but even that isn't simply a number.

People that live at the luxury don't necessarily have the money for it. To bring cars into the picture, an older model Mercedes Benz that's a falling apart money pit costs less than a brand new Honda Civic.

In my mind, the line for middle class is how long you can pay your bills at without working. If you've got enough money that the answer is a while, then you're rich. If you have so much that you're able to fund other people's dreams, then you're wealthy. If you're a short order cook at a diner that saved up enough money to have a go at running a food truck, you're scrupulous.

There's all sorts of caveats, and we can be super judgey about how other people are spending their money (and time) on bad/wrong/frivolous things, but I'd bet that most people here still have to work for a living and to me, that's middle class, even if the cars are flashier and vacations are to a different continent rather than a road trip and staying in motels, for those in the upper middle class.