In Europe some families are still insanely rich from being rich 500 years ago. There's not much being written about them today as many do not seek publicity.

Thomas Picketty's "Capital in the Twenty-First Century" is best known for central its argument that wealth will concentrate in the long term, but it also extensively documents the European generational wealth that was destroyed in the first half of the 20th century. Two wars, a great depression, inflation, and high taxes were enough to permanently ruin the accumulated capital of many families.

So it's true that some families that were wealthy 500 years ago are still wealthy today, but this was not the norm.