It’s not about the properties. It’s about the allure of power.
It’s funny that in spite of all your knowledge in finance you’re still thinking like a millionaire where a fancy house on a nice beach would probably satisfy you. They’re billionaires and ones with an obsession with old money, celebrity and ostentatious displays of wealth*.
The Arab Sheiks are the same, despite creating high tech luxury oasis’s in the middle of the desert why do you think they all invest so much money in European property and spend so much time over there, gallivanting around with royalty, sports stars, supermodels, actors and other celebrities?
You threaten access to that world, couple it with an increasingly hostile population at home and you stand a good chance of getting a few to turn on their boss.
*US billionaires seem to be more concerned with sending themselves into orbit but it boils down to the same thing: Bragging rights.