My friend found his in laws on there, and it said they were billionaires. I don't think so.
Those online estimates of net worths are napkin calculations. They don’t take into account how the person spends their money. You can take two celebrities with similar incomes throughout their career and they can have totally different net worths, because their lifestyles are different.
Depending on the currency used to make the estimate, that can be quite true.
When I traveled to Asia, I literally carried around tens of thousands in cash. I needed it. I spent 3,500 on a souvenir for my son.
Very wealthy people usually have a net worth close to zero because they put their money into trusts or other things like corporations where the “owner” is a piece of paper, not the person.