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.