I've taken hundreds of flights in and between the USA and EU and never once had to show anyone my credit card. In a number of cases, the ticket was booked with someone else's credit card.
For (non-Schengen) international flights, I usually have to show someone my passport.
Did you mean most/all airlines in Japan?
Add Oceania to that. As long as I've been able to produce the proper passport(s) and visas for my journey I've been let on the plane, throughout all kinds of complex journeys.
I have had a round trip flight recently that involved two passports, a work visa, and an ETA, and a total of 5 layovers across 3 airlines. As long as I produced the correct identity documents at any given check in desk, I was allowed to board, without ever producing a credit card.
Didn't happen to me for a domestic flight with JAL recently. I was actually surprised how little they checked; just a QR code was sufficient (although my memory might be fuzzy due to the international flight just before it).
This is for getting tickets printed on the spot, not for using the already printed tickets. People buy tickets online and have it printed later at the airport/station kiosks, which lets you prove your identity abusing the fact that customers realistically don't forge a credit card. It can be an ID/password login at the busy station using unresponsive touchscreen, or a membership card of the airline/train, or maybe even a driver's license, but CC is probably the most convenient(unless...).