This is of course folly. Complex systems need maintenance. Billionaires will still need physical security teams. What will they pay them with when there is no money?

More importantly, why would the head of Bill Gates' security not just kill Gates and take over, since there will be no police and no courts to catch and prosecute him.

These billionaires are nearly all libertarians on steroids. They want the good things that societies (e.g. socialism) bring like courts and police and roads and electricity, without having to pay for them.

What they'll get is Libya, Somalia, etc. Failed states where local war lords kill each other and utilities are scarce. Fucking morons.