Wealth doesn't last beyond three generations? Wasn't that debunked? Outside of external cataclysm or far bell curve "bad luck" I don't think most born into we

Wealth doesn't last beyond three generations? Wasn't that debunked? Outside of external cataclysm or far bell curve "bad luck" I don't think most born into wealth (defined lets say as the investor class that commands "decent" capital holdings) pass poverty on to their kids.