Something that a lot of people don’t seem to realize, even some of the answers already here included, are that net worth does not equal just a pile of money like a cartoon character with a pit of gold coins or literal piles of money.

Net worth is how much everything a person owns is worth.
Including things like real estate, intellectual property, and companies.

For example, Bezos owns about 10% of Amazon. That’s worth about 90ish Billion dollars.

That does not mean he has 90ish billion sitting in an account somewhere.

An analogy that’s more relatable to most people is that by owning a car, it doesn’t necessarily mean someone has 20k in cash at any one time. Their net worth is at least 20k, but net worth doesn’t necessarily mean cash.

Most of the net worth is from those stocks that they own, like Gates with Microsoft. He owned a lot of Microsoft. So when Microsoft gained value, so did he.

So the ownership of these stocks would change (and likely be worth less since someone like Bezos dying would likely lower stock prices) but it just means that part of the company would be owned by someone else.