> if so, what particular mechanisms exist for some truly idiotic child born with a trust of $1M, $10M, or $100M to lose their wealth?

The mechanism of humans to spend and consume frivolously. I know plenty of people who are simply uneducated on financial matters and blew through trusts of a few million dollars thanks to accountants and trustees who enabled them to spend in excess of a sustainable withdrawal rate. They aren't too different from lottery winners, many of whom end up broke. That's why I take the view that class and culture > wealth until you start to get into the nine figures range where wealth becomes more self-sustaining, although even then if you look at the top echelon of athletes and celebrities you see similar examples of self-destruction.

The mechanisms that affect newly minted, publicly exposed figures (celebrities, athletes, and lottery winners) is largely predatory investors and money managers. Predators are a lot more successful at taking advantage of poorly educated athletes, etc. Frivolous consumption, which certainly can affect persons of any financial upbringing, is unlikely to have any material impact on those who simply inherit money and do nothing else of value to society. I believe consumerism could be impactful to truly idiotic persons of inherited wealth (with an equally classless, idiotic family surrounding them). A trust fund baby of average intelligence, brought up in a family practicing at least upper-middle class social norms, would likely be perfectly fine.

> That's why I take the view that class and culture > wealth until you start to get into the nine figures

Class, culture, and wealth form symbiosis much before fortunes of 9 figures.

Personally I believe proper taxation structures are much more effective a method to normalize against inherited wealth.

> Frivolous consumption, which certainly can affect persons of any financial upbringing, is unlikely to have any material impact on those who simply inherit money and do nothing else of value to society.

It's just a function of the numbers, isn't it?

A trust fund has $1 million in assets, 1% fees, and beneficiary withdraws $50k (5%) per year. Based on the historical data at firecalc.com, within 30 years, there's a 50% chance the fund has hit $0.

Just in fairness to the non-idiots who depleted their low single digit million trust funds, it's been much more the rule than the exception.

So they might have to go work for Goldman Sachs for a few years after graduating from Wharton, but that's not too big a burden in order to avoid bankruptcy.