I think the biggest upset that billionaires cannot do is the most important thing money should buy. Billionaires cannot afford his own biological children without risking his whole wealth. In particular, billionaires cannot simply afford many (say, 20) biological children.
Okay some comparison.
There are 2 types of billionaires. Females and Males. Obviously female billionares cannot have 20 biological children, nor can they do so on 1900. So let’s ignore the trivial case.
In 1900 China (not sure about europe), it’s simple. Have tons of concubines. Have tons of children. Period. It is easily done. Many are actually doing it.
Bob and Sally like each other. They like licking each other genitals. They plan to combine their genes and produce viable offspring to propagate their species.
Then government come and say, “Okay Bob and Sally, here is what the deal is.” Bob you got to be loyal with Sally and that means not fucking other females. Sally, you have the right to divorce Bob at will and collect his whole paycheck.
“If that’s what the deal is, I am out,” said Bob. Now, Sally, can’t choose Bob. Sally need to choose some idiots that do not value his freedom, which may not be her best choice. After all, it’s those who are poorer that do not mind risking all his wealth for a girl.
It doesn’t work on female. Every male know how attractive a girl is without having to rely on what other males think. Females are simple. Pretty, smart, big tits -> attractive.
Males are complex. Some are tall, some are handsome, some are funny, some are smart. Most of men quality is hidden.
The cost of sharing is also different. In ancient time, there is no blood test. Men that share a women will have a hard time deciding which kid to support. So waiting for other men to have her first is costly for men (unless he can knock her up and run).