2,000 gold bars were stopped out of iraq. and that is just what was stopped / reported.

Dictators and autocrats may or nay not have cash sitting in a bank account, but there are most likely multiple with $1B in gold.

Gold is value, you cannot take it to a grocer and buy food.

It is much more feasible for Jeff Bezos to sell a billion dollars worth of Amazon tomorrow or Bill Gates to sell a billion dollars worth of MSFT tomorrow than it is for Elon to sell a trillion dollars of SPCX even over a year's time

I get that net worth is more than just cash, and that is not what I meant and it's pretty obvious that isn't what I meant. It may not just be cash on hand but if an asset is completely illiquid at it's purported value, is it actually worth that?

It is, because of the time component of money. Money is a way of storing the value of labor in a manner less affected by time. If you sell it all at once, its value is greatly reduced. All investments include that time component. Point-in-time net worth doesn't have much value as a measurement in part because of this.

Somewhat doubtful. (The first part of your statement, anyway. Of course the difference between abstract "value" and hard, spendable "money" is a thing.)

Like Mr. Hanson said in my sibling comment, some rulers are (or were!) bound to have amassed incredible amounts of resources. For historical/non-present-day examples, consider looking into figures like Jakob Fugger or Mansa Musa.

I have no idea why the adjusted net worth of people who died centuries ago would have anything to do with money in the modern day. And at a glance, neither of your examples had billions of dollars in cash, which is the point I was making. They may have had a lot of value tied up in illiquid investments, which is exactly like Musk's valuation.