I mean if we’re talking about top 1% you’re probably right, but I believe in the top 10% there’s a bit of movement. Out from it and in to it from below.

And there are plenty of examples of people going from being extremely rich to being bankrupt and never recovering. It’s not impossible, but probably requires quite a lot of effort and/or stupidity. For instance, when Iceland went based and let its banks fall, this guy went from being worth $1B to -$750m. https://en.wikipedia.org/wiki/Björgólfur_Guðmundsson