You seem unaware of the population of accidental Americans. When a Dutch couple gives birth on US soil before returning to Europe, that child automatically a birthright citizen of the US. They can grow up having never set foot in the US (apart from birth), and for the rest of their life they have a legal obligation to file US tax and declare to the US all their Dutch income & bank accounts even if they are below that $120,000 line. They also get targeted for discrimination along with all other Americans by banks who don’t accept Americans (even if they are also Dutch). They have to pay a US accountant upwards of $300/year for the rest of their life just to file that zero.
It’s also worth noting that an income of $120k goes much further in the US than it does in Europe (where they might be living).
So obviously a lot of accidental Americans have become motivated to renounce. But if they already own a home, you can see the problem. I would not say owning a home makes someone “rich”. They still need to work to eat and to maintain the home.