It's not only that, it's the fact that the stores have externalised the checkout process to customers themselves.

I could never understood why should I, as a client, do the work that someone else can do for me (and more reliably, of course)? It's win-win, I'm not stressed at doing something wrong, I can do something else while my products are checked out and that person doing the product checkout also has a job.

But because it sounds tech-y and more automatic-y lots of tech-literate people fall for all of this, I don't see what's more automatic in me doing the same work that another person used to do.