They can convert that money into control/ownership over land and people.

If the economy is broken for everyone else, but you control the survival of people (through destroying or blocking labor laws, wage protections, public insurance, and eventually distribution of food and water, etc) and the space around those people (land, property), that control will outlast the economy and potentially the government. That’s because they can afford their own monopoly on violence in a given domain, if the state’s monopoly falls apart.

We’re not quite there yet, but fiefdoms could yet come back in style.