Who is happier, the person who always wants, and always buys what they want? Or the one who learns to not want so much, and is therefore always satisfied?
Once you can afford something that was way out of reach before, you buy it and after the first few moments you realize it is not as great as you expected. Do this a few times, and you'll learn what is important. The more wealthy people I know do have a slightly above average car and house, but IME the biggest difference is that they have far more extreme - both in amount and in price - experiences, i.e. weekend trips, fine wining and dining etc.
Maybe financial independence isn't for you. It doesn't suit most people in fact - most choose the greater financial security and predictability of a decent job. This is very helpful if you are an entrepreneur as you can hire people much smarter and more able than yourself.
Higher earners tend to just upgrade and spend more (apartment, clothes, restaurants, hotels etc), and aren't really living that differently - that lifestyle can certainly soak up maximum income achievable in a salaried job.
I think this is what the article inadvertently pointed to, that the higher salaries could lead to a sense of frustration that nothing really changed.
J suspect that ceteris paribus, being frugal reduces happiness - by definition, it's not getting things you want to get.