What I see them used in is parking garages

You don't pay with them but you get them back as change in parking garages that have unattended exits. You either pay by credit/debit card or insert nice crispy paper currency. If paying by paper, you get change back in those 1 dollar coins. I don't know how else they'd do this as I'm seeing fewer parking garage attendants and more of these machines. I suppose they could dispense crispy one dollar bills but it's the paper that tends to jam them.