R79 - Those "billions" are mostly non-liquid: art, land, horses, etc. And in fact, although hardly poor, the Queen doesn't any longer even make it into the Top Ten richest people in the world. The richest royals in Europe are the Lichtensteins and the House of Orange-Nassau (think Dutch Petroelum, which they sold and made untold billions off of - the jewels in the Dutch royal safes make QEII's collection look modest by comparison).
What people are "worth", especially in cases like this, where the two sons of the next King live very richly on what is, in actual personally earned wealth, only the income from their trusts, is somewhat a matter of smoke and mirrors.
The polo ponies, the cars, the servants, the grand homes, a large portion of their wives' wardrobes . . . are supported by the three million quid a year Charles gives each son, and by the Crown Estates properties in which they live but didn't have to buy OR renovate. It cost about 3-4 million to renovate Frogmore Cottage and Kensington Palace Apt 1A for Kate and William. It was all paid for by the Sovereign Grant.
So the "billions" are mostly tied up in stuff the Queen and Charles can't sell or rent. Balmoral and Sandringham belong to the Queen, everything else are Crown Estates property and any revenue they generate goes back into the Crown Estates and thence back into the Sovereign Grant (used to be the Civil List).
Yeah, they have lots of real estate holdings, investments, etc., just like other wealthy people. What did you expect?
But the way they live is really supported by the optics of Clarence House, KP, Windsor Castle, BP, the servants, the antique cars and limos . . .
Like most wealthy people, they don't touch capital, only revenue.
Even her art collection is vested in the state now, with a portion set aside for her personal inheritance. It's one of the world's premiere personal art collectins, and contains not only major Old World Masters and Impressionists, but antique artefacts of china, crystal, silver, furnishings, etc. You can't sell those - they're worth something on paper, but really, you can't sell them, they only have value within the context of their royal history.
Some of it is smoke and mirrors. The Queen's actual personal worth these days is estimated at about $600 million USD, She's a piker next to ex Mrs Bezos or Mrs Gates, let alone King Willem of The Netherlands and the Grand Duke of Lichtenstein.
It's plenty, for sure. But there is a lot of exaggeration around it.