It's also a way to decrease the amount of labor required to produce an essential service, which is good. Might as well complain about the combine harvester killing jobs in the agrarian sector. Do you want to work as a field hand who harvests grain with hand tools? Hell, do you actually want to work as a cashier?

If stores exploit the lower costs, that's entirely on our societies failing to distribute wealth properly or have even a semblance of a functioning market. Don't blame technology for that.