Few people now remember it, but back in the earlier days of commercial aviation flying was a breeze. You could walk up to a counter, buy a ticket, walk to the gate and walk on.
Yeah, I remember the days of "arrive 30 minutes early for international flights just to be on the safe side". Now the "rule" is you can't even fly if you arrive that "late" for an international flight.
People's Express Airline. A low-cost airline from the 1980s.
From what I understand, a perfectly viable procedure was: walk to the gate, wait until they call out "all aboard", push and shove for the good seats, take off, pay in cash when the crew comes around to collect tickets.
It was that way for a long while.