First, it’s worth noting that society is unlikely to collapse and money to become meaningless. Even during a time of catastrophe, it’s useful to be able to trade IOUs. Maybe I’m good at skinning animals and maybe you’re good at fixing equipment. I can skin the rabbit that you caught but what can you do for me, if I don’t have anything that’s broken for you to fix? If you give me money, then I can go look up the guy who’s good at growing potatoes, and he can use my money to hire you to fix his windmill.
Money is useful for society to encourage people to help each other, and that’s even more necessary during hard times, not less.
Secondly, your average billionaire doesn’t have a bunker. If you’re afraid of catastrophe, you’re unlikely to be the sort of person who is willing to take the risks needed to get rich. The sort of person who dreams of owning a bunker is generally the sort of person who’s also afraid that if they put their money in the bank that the lizard people are going to take it. A billionaire doesn’t put their money in a bank because they believe that they’ll make more money on it in a brokerage than a savings account.
In a sufficiently dire situation, maybe people would turn to cannibalism. But, even when you look at cases like the Donner Party, most people don’t.
Humans have lived in everything from the sand-strewn desert to ice and snow wastelands, successfully, for thousands of years. A healthy, physically fit human being is generally going to do better moving around to find a source of food than sitting around in a bunker, thinking that food will just magically appear out of the concrete.
In both the Donner Party and the Andes plane crash survivors, the young healthy men were able to successfully walk to safety and probably would have done better to have immediately done so rather than hang out dealing with women, children, and old folks.
If the bodyguards like the family that they’re guarding then they’d probably like normal humans and try to help the people. If the family was populated with horrible people then, at the most, I’d expect the guards to take some food and start walking.
Cannibalism isn’t likely to be on the table unless they’re literally trapped in a room. And then, we’d expect that they’d eat people who died naturally, rather than some sort of murder-fest. That’s not how humans behave in these sorts of situations.
No, they’re people. Mr. T was a bodyguard. He was just a guy who was physically imposing and turned that into a career.
Some of them are nice, some are assholes. The assholes probably don’t last long as employees since who wants to hang out around them?