The very wealthy do shop at warehouse clubs, Walmart, etc. You won’t see them being walking advertisements for clothing lines, either. They do buy quality clothing, but they aren’t overtly branded, unless they’re casual, work or sports clothing. They may drive nice cars, many will own a regular 90s model Pontiac or something. They also don’t plan their money for years, rather in centuries. There’s a difference in behavior and attitude between old money and nuveau riche, as well.
Have you ever wondered why it’s never been different?