Ten Wealthiest Families in the World, in order of richest first:
The Waltons
The Mars Family (the Walton's of the candy market)
Koch Brothers/Industries
Saudi Royal Family (Meghan, take note!)
Wertheimer Family - Chanel
Dumas Family - Hermes
Van Damme, De Spoelberch and De Mevius Families - Anheuser-Busch
Boehringer, Von Baumbach Families - Boehringer Ingelheim (Pharmaceuticals)
Mukesh and Anil Ambani - Reliance Industries (petrochemicals, refining, oil and gas - India)
Cargill, MacMillan Families - Cargill - commodities agri-giant
The Windsors are pikers next to these people. The Queen's assets, most of which are in real estate, art, jewels, homes, horses, etc., reach barely a billion. Charles's personal worth, on paper, is perhaps $200-$300 million, depending on who is answering the question, again.
William and Harry are only worth $40 million each, and that's on paper in one trust fund whose principal they never touch, only the income, which amounts to what a highly successful solicitor or private health specialist would make - before taxes.
They look wealthier because they live wealthier, but without having had to pay for it - e.g., the Cambridges live in a historic palace in central London; so, of course, does the Queen; Clarence House is also part of the Crown Estates; so is Windsor Castle.
They live in those places but didn't have to buy them. The Queen owns Balmoral and Sandringham personally, but she didn't buy them, her grandparents and great-grandparents did. Most of her jewels are heirlooms and were either inherited or gifts from other nations; she has, of course, bought some new stuff and altered some old stuff, but most of it she didn't have to buy. She has probably spent more of her own money on the impressive art collection and her stables.
So they live like royalty, they look like royalty, they were the jewels of royalty . . . but in almost all respects, they haven't had to buy that: it was already there. Maintain and renovate, yes; Buy, no.