Reading the other reply, I guess it's about 'payment' for taking a hitch hiker. As fuel became expensive now, the driver can no longer afford the other two options in exchange.
People used to have bumper stickers that said "grass cash or ass" as in payment methods for a ride. It often meant they were willing to give a stranger a ride. As fear and irony took over our nation it eventually became a shitpost. No one hitchhikes anymore tho