I use my AMEX for the sky miles. Over the years we have gone to Hawaii (3 x’s), Japan, Costa Rica, Niagara Falls, Chicago & St. Martin (2x’s) for between $5 and $60 (foreign tax) per round trip.
I use cards too but the gas thing is a no win deal. I can see where they are coming from.
I was eyeing up my point balance... saw I could swing a round trip to Japan in first class for a song. Like $5...