The cashiers were stressed because the corporations treat them like shit. I suspect in the run-up to introducing self-checkout, they made it even worse, to justify charging us to work for them.
That said, I admit that while I hated the idea at first, because people would lose their jobs, I like self-checkout better.
HOWEVER, ideally, we’d have human cashiers, well-treated and well-paid, and enough of them to ensure a short wait. But, that’s not as profitable, so we get what we have now. Because, billionaires are ruining everything, and at an accelerated rate.
Years ago, I read a quote from a researcher who concluded that every disease is an infection.
I know that’s not commonly believed, that’s why I remembered the quote. But, maybe it will turn out he was right, someday.