Except his actual net worth is probably a fraction of what his theoretical net worth is. It's assumed for instance that he still has access to all those bitcoin

Except his actual net worth is probably a fraction of what his theoretical net worth is. It's assumed for instance that he still has access to all those bitcoins, but something could have happened to that wallet. There's also the difficulty of actually converting those coins into something the average business will accept. It's like suggesting that handing someone a billion dollars in un-vested bonds suddenly makes them a billionaire, but in reality there not really any richer currently than they were before, although in some theoretical future they might be (assuming they hang onto the bonds till they vest and can cash them in).