You don't have to stand at the car while it charges so the time comparison should really just be how long it takes to plug in and pay. This assumes the charger is at a location you are already visiting. If we accept that assumption you also save the time you went out of your way to a gas station.
That is what I meant. The OP is at the airport and wants to set the car charging. This really doesn't take long at all if the charger is working.
If the charger isn't working that's because someone didn't fix it. That's usually because there isn't a maintenance contract and people didn't pay enough for said maintenance contract. When you buy gas there are use taxes for road maintenance. Kinda like that.