I'll tell you yet another way you can have a "net worth" of a million dollars, and no access to money..
Trusts. I once knew someone who had a trust set up for them. Except, well, the money wasn't accessible for some long period, according to the terms of the trust, and the trustee wasn't interested in handing out any of the money (and quite possibly interested in stealing it, from what I could tell). Legally, this money was "hers", but she had no way to get access to any of it. This is actually a very old pattern dating back to the Victorian period and before.
There are lots and lots of ways to have money tied up in "illiquid assets" which you can't sell, can't borrow against, and basically have no access to. There are also people who supposedly have "vested money" in pension plans, but can't access it. There's all kinds of stuff like this.
Heck, on paper Amtrak has lots and lots of assets. But they aren't saleable to anyone at better than scrap prices, and banks won't even lend against most of them any more. So Amtrak is chronically short on cash.