If I'm physically able to do it, would otherwise need to wait longer to get through a cashier line, and don't have anything else to do with my time while waitin

If I'm physically able to do it, would otherwise need to wait longer to get through a cashier line, and don't have anything else to do with my time while waiting in the cashier line it seems like it's to my benefit to use the self-checkout on principle. It saves me time and costs me virtually nothing.