Dollars are created by the Federal Reserve, not Congress.
Banks are backed by FDIC insurance which, although it has been able to pay each claim ever filed, did get cold feet in the 2015 crisis and obviously does not hold a dollar for each insured dollar. In fact some cursory research shows they hold about $6 for every $10000 and in a major collapse like the 2015 crisis, which could have been even worse, they could very well get in trouble.
Banks are backed by FDIC insurance which, although it has been able to pay each claim ever filed, did get cold feet in the 2015 crisis and obviously does not hold a dollar for each insured dollar. In fact some cursory research shows they hold about $6 for every $10000 and in a major collapse like the 2015 crisis, which could have been even worse, they could very well get in trouble.