We already know that spending is higher with credit cards, i.e. humans actually spend less when they have to pull out their cash for every purchase (hardly anyone does that anymore, it's not what's portrayed on the screens we watch).  And we know that the vast majority of youth take on the habits they are directed to by their society, so of course credit card use is more common than ever.  They've only existed for a few decades.  It's not a problem to those who don't partake, it may or may not be a problem to those who do.