It is collapsing right now. The debt problem is not only national but corporate. That seems to be where the real problem is. American corporations are deep in debt and don't have a way to pay it. There is a bond crisis going on right now that is suspiciously underreported by most media as the virus and lockdown are dominating the news. But corporate bonds that used to be considered investment grade are dropping down to junk status. Much of the QE we are seeing is going toward propping up the failing bond market. So the premise of the original post, that people saving money might be harming the economy, is a red herring. Individual citizens, most of whom might be holding onto a couple thousand dollars cash at the most, are not harming the economy. They are helping it. The notion that individual's holding cash could harm the economy comes from the fear of the inevitable. They want to lock down the money in bank accounts so they don't have to print more. But when the fear of printing more money leads to lockdowns of cash in addition to lockdowns of people, it is not a good sign for the future of the economy. When this does spin out of control, it will be because of corporate bailouts, not because of individuals holding cash. The bond crisis is in the trillions of dollars and growing.