But it's also a dollar that's been spent - paying for school supplies for the daughter of the welder employed by the manufacturer, the medicine the truck driver's mom needs, and a few drinks at the bar for the retired vet who ran the backhoe for the bunker.
The economy isn't a closed system, so anything that gets the super rich to spend their money rather than stockpile it will benefit the economy as a whole.
Especially if you don't have any political clout or an army to back it up.
Would donating $5 million really help in some catastrophic event? Especially when compared to the multi-billions that nations spend each year?
Money is probably at peak value: more valuable than it has ever been, but people are realizing its limitations and it will probably never again be as valuable as it is today.
Other forms of value are ascending. That's why people who rely on money and armies for their livelihood are so scared.
If you want to help the world, money and armies are not the tools to use. Start with your time, human time will never be less valued than it is today.
Every dollar you spend on your bunker is a dollar you don't spend helping the world keep out of the sort of trouble that would make your bunker necessary.
I'm not saying you aren't entitled to spend your time and money however you like, but there is a mathematical sense in which the goals do conflict, even if only via opportunity cost.