Not necessarily true. More money at that level isn't about more material possessions or even more services: it's about more power and influence. It's playing toward oligarchy.
I didn't say anything about possessions and purchasing power, the competition in that echelon is about who has more ability to bend the world around them, thus the dick measuring comment.
The personality required to "earn" a billion dollars off the backs of your working employees is exactly why it will never be enough for them. Have enough money that all your grandchildren's entire lives are paid for? Then it's now about control. Who can you influence and how much of your shitty mentality can you project onto others?
Billion dollars grows by 70 million passively per year. Next year you have 1,070,000,000 which grows by 74.9 million and next year by 80 million and so on. Basically the more money you have the easier it is to make more money.
Also, a billionaire doesn't have billion dollars in the bank. That's not what being a billionaire means.
Cumulative interest is absurdly powerful. Turns out that the best way to earn a fuckton of money is to start with a heckton.
Tangentially related: a friend told me that they worked out that £1,000,000 in the bank/invested in safe options would accrue enough interest that you could retire and have a decently comfortable income just off of the interest (meaning that the million pounds would remain untouched and able to be inherited by kids of whatever).
It weirdly reminds me of growing things like moss, yeast (for bread) or fungi. It takes far more time than work; you set up the conditions for them to grow, and then you leave them to their own devices for a while. I can't imagine treating money like this; growing up poor means that no matter what level of financial security I achieve as an adult, I will always be acutely aware of exactly how much money I have, and how fast it is growing or shrinking.