...Really? That's a straight detriment in my book, as a customer.
I would generally prefer to support a union shop, but I'm extremely fond of self-checkout—and, in fact, further upstate, Wegman's has introduced a self-scan app that you can use to tally up your total as you shop, and just scan a code at the self-checkout register with your phone on the way out to pay.
One of the worst things unions can do is try to "protect jobs" at the expense of technological advancement, customer service, or improved product.