Years ago a study came out that most Americans couldn't afford an emergency $400 medical bill. (For non-Americans, $400 for an emergency is nothing.) I doubt the situation has improved.
People who said they'd pay using a credit card got reported in the media as being "unable to afford" the expense. The original study might have been an interesting finding on the transition to a cashless society, but for millions of Americans, paying using a credit card is the default rather than carrying cash and dealing with change, and not actually indicative of lacking funds to pay for something.