It’s absolutely an issue. I was in Turkey and could not get the luggage trolley dispenser to accept my card to give me a trolley. I had to carry my bags across

It’s absolutely an issue. I was in Turkey and could not get the luggage trolley dispenser to accept my card to give me a trolley. I had to carry my bags across the airport. Annoying, but at least it wasn’t a flight! People come to airports from all over the world. You are going to hit every single payment edge case at an airport. Also people in airports often have limited ability to communicate. Consider: you arrive in Germany on an international flight, go through immigration, then wish to take a connecting local flight to your final destination. When you’re in landside transit you may have no working SIM card or any kind of communications with your bank. That’s why flights are based on confirmed itineraries and not payment at the check in counter.