Most generational wealth dissolves pretty quickly unless the heirs are industrious. It's a problem that solves itself naturally.
In any case, it's a lot easier to seem industrious if you start out with a huge pile of cash than without. If you park it all in t-bills and live within the coupon income you won't earn any prizes but you won't suffer any real economic anxiety or accusations of impropriety either.
Regardless, the OP was not necessarily talking about the generational wealthy, they quite literally said the "idle rich". And there will always be a fair number of those folks, regardless of whether it was multi-generational or not.