You really dont get it? Because real billionares have the money and you dont.

Journalists just told everyone you are billionare, but you're just average SWE on $120k / year and absolutely no money for hiring small army of guards. Neither your own government agencies keep your back protected like they do for usual high profile people.

Now go find a proof for mafia that you are not in fact have a billion bucks on USD stick.

This has happened in this Satoshi hunt multiple times already. I mean finding that some random crypto related SWE is Satoshi when they are not.

Satoshi is a paper billionaire - he can't use a small fraction of his "wealth" to hire proper security. Simultaneously his "assets" are much more attractive to criminals. Imagine holding a regular billionaire hostage and demanding they give you a billion dollars. They'd probably have to sell 1B worth of stock, then convert it to cash (or crypto), etc. all of that requiring multiple interactions with different people and institutions.

Even if you put a gun to Bill Gates' head, signing over all his wealth to you would still require a lengthy process, not just handing over some keys.