Last year, the Fed released a report (then analyzed by the New York Times) that said for Americans under the age of 35, their credit card debt had fallen to its lowest level since 1989. Continuing:
Some older Americans have also been shedding credit card debt since the financial crisis that began in 2008. But for no other age group has the decline in the proportion holding credit card debt been more rapid than it has been for young Americans — who are often referred to as millennials — the data from the Survey of Consumer Finances shows.
This doesn’t mean that millennials are shying away from credit cards necessarily, rather they have much less credit card debt, but the two are sort of connected.