I love the self-checkouts, I have been using them since 5 years now and only very rarely do I still checkout out at the cashier. Here in Switzerland I also don't seen any sign of supermarkets backing out of it, quite the contrary.
I guess the article is specific for the US or the UK. I don't think the technology is a failure at all, the problem seems more specific to the culture.
Same in Slovakia. I love self-checkouts, been using them preferably. Paired with scanning items to the store app as I pick them from aisle and then just scanning self-checkout QR code so all the items neatly import to checkout register and I just pay for it and go (Kaufland, Tesco). It's been really good experience.
I guess the article is specific for the US or the UK. I don't think the technology is a failure at all, the problem seems more specific to the culture.