Many of these billionaires they're referring to are paper stock billionaires. It gives you access to maintain control/takeover other companies. For example, Elon made an argument that his package payout (if fulfilled) was so large because it served him to be able to retain control of his company.

Another example would be taking over media companies like what Bezos did, the side effect would be being able to waylay/hide any dirty laundry.

Do you have a want to please millions of people whose lives are improved by exactly the product that your company sells? I could certainly do without that, but it does sound nice.

I'm not sure there is but if you create a company that successfully serves the world's 8 billion population it often ends up worth more than 12.5 cents per head. Or else it maybe isn't providing that significant a service.

With nearly all the billionaire PG mentions the money is the company valuation rather than cash in the bank.