>>1986239It's goofy.
You can buy single trip ticket cards at kiosks, otherwise you're stuck on their unholy marriage of an oyster card and a prepaid credit card. For Regional Rail, you can board and buy a card from the "conductor" (that they haven't gotten rid of yet, shockingly). They have to have that, because the turnstiles in Center City need a swipe and stations out in fuck-all don't have kiosks to buy tickets most of the time.
Buses still take cash, if the machine is actually working on the bus you're on.