How could a family that once had a net worth of over one trillion dollars be in need of this money?

Sincere question:

Why would the Rothschilds, one of the richest families on the earth, be selling off their private collection of heirlooms, art, and historic pieces when these pieces often serve as a symbol of their high status and power?

When you browse the goods, they aren't just selling a few items here and there; they are. No, it's a two-week auction giving away piece after piece...

How could a family that once had a net worth of over one trillion dollars be in need of this money? Or is something else going on here?