Inflation is balooning. Even before the recent large expansion of the money supply, holding cash is a losing proposition. Makes way more sense for emergency expenses to go on credit while you liquidate assets, rather than having cash sitting around waiting to get obliterated via invisible redistribution.

I read this more as "lots of rational Americans have the collateral or access to collateral for a loan, and some subset of those can afford to get obliterated by inflation by holding large sums of USD."