To me the biggest luxury in the world is being able to live reasonably happily within one's means and not having to worry about it. To think about one's finances as little as reasonably possible while not overspending and still getting to have fun with it sometimes, with the confidence that a reasonable amount of it is being saved for retirement someday. It doesn't require being rich, just having a sense of the value of things and the value of one's own time and life and life experiences, and getting good at quick, rough estimates of one's financial situation.
The more I have to worry about money the less happy I am, even if it's tons of money and I'm just figuring out how to best utilize it. Obsessing over money leads to a person thinking about nickel-and-dime bullshit throughout the day, every day. That's fun for some people, I get it, but they need to realize they're wasting time thinking about nickel-and-dime bullshit because it's fun to them, not because it's practical or pragmatic to do so. And that's fine if they want to do that, but they just tend to be miserable people to spend time with who are always missing the forest for the trees when living life.
In my opinion spending money is usually more work than it is worth, even without considering the time it takes to earn said money. Like, you have to go to the store, keep track of another item in your home which you basically never use, throw it away etc. Or go to a restaurant, order things, wait for 30 minutes just to eat and then wait to pay and so on. Or going on trips to exotic places, which mostly entails wasting a day sitting on a plane just to visit a country with barely functioning infrastructure.
So to me it looks like people work hard to spend their money for no reason at all and that is what keeps them miserable.
Why pay $10 for a salad when $20 can pay for a week of salads customized exactly the way you want. (and organic)