Stuff like that has never been unique to self-checkout. I remember in my teens in the 90s you'd run into things like the credit card system being down or the check-checking system being down when you went through the line with a physical cashier, or some barcode not scanning because it's some niche product that didn't make it into the system. Or you only had a $50 on you and the cashier was struggling to make change because it was too early/too late in the day, so you had to hold on while they flagged down someone who could help them open another register to break it. Or there was a coupon being weird, or, or or...there was always something now and again. If not for you, for someone ahead of you in line.

Basically, minor inconveniences always happen now and again regardless of your method of checkout or payment. Feeding your own anxiety by stressing out whether you look stupid because a touchscreen has stumped you for this or that reason is unproductive.

Like--yeah, I get it. I've felt frustration too. I have felt the same things you talk about.

But I consider my own feelings a "me" thing? I've always felt that was a thing I had to overcome in myself, my own impatience, my own frustration over an everyday minor blunder. My own fears that I look "stupid".

Blaming the world around me (such as the self-checkouts) for being imperfect is...unrealistic, to me? There will always be minor things, minor delays--it's just a facet of life that will never change.

So it's always seemed to me that it's more productive to be zen about it. Especially when looking at my own memories I remember just as many minor checkout "upsets" when going through a line with a physical cashier as I have encountered in the self-checkout. Small errors happen regardless of system, so why not learn to flow with it?